Implantable device header and method

ABSTRACT

Systems and methods for implantable medical devices and headers are described. In an example, an implantable medical device includes a device container including an electronic module within the device container. A modular header core includes a header core module including at least one bore hole configured to receive a lead, an antenna attachment module coupled to the header core, and an antenna engaged with the antenna attachment module. The antenna attachment module is configured to locate the antenna in a selected position with respect to the header core module.

CLAIM OF PRIORITY

This application is a continuation of U.S. application Ser. No.13/711,670, filed Dec. 12, 2012, which claims the benefit of priorityunder 35 U.S.C. §119(e) of Kane et al., U.S. Provisional PatentApplication Ser. No. 61/569,936, entitled “IMPLANTABLE DEVICE HEADER ANDMETHOD”, filed on Dec. 13, 2011, each of which is herein incorporated byreference in its entirety.

TECHNICAL FIELD

Various embodiments described herein relate to apparatus, systems, andmethods associated with implantable medical devices.

BACKGROUND

An ambulatory medical device, such as an implantable medical device(IMD), can be configured for implant in a subject, such as a patient. AnIMD can be configured to be coupled to a patient's heart such as via oneor more implantable leads. Such an IMD can obtain diagnostic informationor generate therapy to be provided to the patient, such as via thecoupled implantable lead. Examples of such devices can include cardiacrhythm management (CRM) devices including one or more of implantablepacemakers, implantable cardioverter-defibrillators (ICDs), cardiacresynchronization therapy devices (CRTs), neural stimulators, or one ormore other devices. Such devices can include one or more electrodescoupled, such as via the implantable lead, to circuitry located on orwithin the IMD. Such circuitry can be configured to monitor electricalactivity, such as to obtain information indicative of electricalactivity of the heart. In one configuration, IMDs have a header that iscoupled to a container that houses much of the electronics of the IMD.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example IMD according to an embodiment of the invention.

FIG. 2 shows an FTIR spectra of an example polymer header according toan embodiment of the invention.

FIG. 3A shows five images of a device according to embodiments of theinvention.

FIG. 3B shows a surface roughness calculation according to an embodimentof the invention.

FIG. 3C shows a photo micrograph of a device according to an embodimentof the invention.

FIG. 3D shows a photo micrograph of a device according to an embodimentof the invention.

FIG. 4 shows graph of laser speed versus surface roughness according toan embodiment of the invention.

FIG. 5 shows graph of surface roughness versus failure strength of adevice according to an embodiment of the invention.

FIG. 6A shows an example side load testing apparatus according to anembodiment of the invention.

FIG. 6B shows a test specimen according to an embodiment of theinvention.

FIG. 7 shows a graph of failure strength in side load testing forvarious devices according to an embodiment of the invention.

FIG. 8 shows a side view of an example header of an IMD according to anembodiment of the invention.

FIG. 9 shows a side view of an example header of an IMD according to anembodiment of the invention.

FIG. 10 shows a front view of an example header of an IMD according toan embodiment of the invention.

FIG. 11 shows a back view of an example header of an IMD according to anembodiment of the invention.

FIG. 12 shows a perspective view of an example header of an IMDaccording to an embodiment of the invention.

FIG. 13 shows an example identification tag of an IMD according to anembodiment of the invention.

FIG. 14 shows an example identification tag of an IMD according to anembodiment of the invention.

FIG. 15 shows an example antenna and antenna support of an IMD accordingto an embodiment of the invention.

FIG. 16 shows an example header of an IMD according to an embodiment ofthe invention.

FIG. 17 shows an example header core of an IMD according to anembodiment of the invention.

FIG. 18 shows an example header of an IMD according to an embodiment ofthe invention.

FIG. 19 shows an example header core of an IMD according to anembodiment of the invention.

FIG. 20 shows an example mold apparatus for forming a header of an IMDaccording to an embodiment of the invention.

FIG. 21 shows an example mold apparatus for forming a header of an IMDaccording to an embodiment of the invention.

FIG. 22 shows a cross-sectional view of an example header of an IMDaccording to an embodiment of the invention.

FIG. 23 shows an exploded perspective view of an example header of anIMD according to an embodiment of the invention.

FIG. 24 shows a perspective view of an example header of an IMDaccording to an embodiment of the invention.

FIG. 25 shows an exploded perspective view of an example header of anIMD according to an embodiment of the invention.

FIG. 26 shows a perspective view of an example header of an IMDaccording to an embodiment of the invention.

FIG. 27 shows a back view of an example header of an IMD according to anembodiment of the invention.

FIG. 28 shows a side view of an example header of an IMD according to anembodiment of the invention.

FIG. 29 shows a top view of an example header of an IMD according to anembodiment of the invention.

FIG. 30 shows a side view of an example header core of an IMD accordingto an embodiment of the invention.

FIG. 31 shows a cross-sectional view of the example header core, thecross section taken along line 31-31 of FIG. 30.

FIG. 32 shows an example forming fixture and bending tool for formingwires of a header of an IMD according to an embodiment of the invention.

FIG. 33 shows an example forming fixture for forming wires of a headerof an IMD according to an embodiment of the invention.

FIG. 34 shows an example bending tool for forming wires of a header ofan IMD according to an embodiment of the invention.

FIG. 35 shows an example mold apparatus for forming a header of an IMDaccording to an embodiment of the invention.

FIG. 36 shows an example mold apparatus for forming a header of an IMDaccording to an embodiment of the invention.

FIG. 37 shows a component of an example mold apparatus for forming aheader of an IMD according to an embodiment of the invention.

FIG. 38 shows a perspective view of an example header of an IMDaccording to an embodiment of the invention.

FIG. 39 shows a cut-away view of a seal plug of an example header of anIMD according to an embodiment of the invention.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings that form a part hereof and in which are shown, byway of illustration, specific embodiments in which the invention may bepracticed. These embodiments are described in sufficient detail toenable those skilled in the art to practice the invention. Otherembodiments may be utilized and structural, logical, and electricalchanges may be made.

FIG. 1 shows an example of an IMD 100 according to an embodiment of thepresent disclosure. Examples of IMDs 100 can include cardiac rhythmmanagement (CRM) devices including one or more of implantablepacemakers, implantable cardioverter-defibrillators (ICDs), cardiacresynchronization therapy devices (CRTs), or one or more other devices.Other examples of IMDs 100 can include neurostimulators including spinalcord stimulators, deep brain stimulators, peripheral nerve stimulators,or other similar devices. The IMD 100 includes a metallic devicecontainer 102 and a header 110. In the example shown, the header 110includes a number of electrical contacts 112 to couple to additionalcomponents such as lead wires. Although the embodiment shown in FIG. 1includes three electrical contacts 112, other embodiments of the presentdisclosure can include other configurations, such as configurationsinclude more or less than three electrical contacts 112. The header 110is attached to the metallic device container 102 at a surface 114 of themetallic device container 102.

In one example, the header 110 is formed from a polymer material. Apolymer can provide a number of desirable features, such asbiocompatibility, strength, resilience, and ease of manufacturing. Inone example, the header 110 is molded separately from the metallicdevice container 102, and later bonded to the metallic device container102 using an adhesive. In a second example, the header 110 is molded inplace (overmolded) and contacts the surface 114 of the metallic devicecontainer 102 during a curing or hardening process. In the secondexample, no additional adhesive is needed to attach the header 110 tothe metallic device container 102.

In one example, the polymer material of the header 110 includes athermoset material. In one example, the thermoset material of the header110 includes a polyurethane thermoset. In one example, a polyurethanethermoset includes combinations of polyisocyanate and polyol.

In another example, the thermoset material of the header 110 includes anepoxy material. Epoxy is a copolymer; that is, it is formed from twodifferent chemicals, namely a resin and a hardener. The resin mayconsist of monomers or short chain polymers with an epoxide group ateither end. The hardener may consist of polyamine monomers, for exampleTriethylenetetramine (TETA). When these compounds are mixed together,the amine groups react with the epoxide groups to form a covalent bond.Each NH group can react with an epoxide group, so that the resultingpolymer is heavily crosslinked, and is thus rigid and strong. Theprocess of polymerization is called “curing,” and can be controlledthrough temperature, choice of resin and hardener compounds, and theratio of said compounds. The process can take minutes to hours.Thermoset materials other than epoxies may cure using other polymercrosslinking reactions.

In one example, the epoxy is injected into a mold and cured into thefinal desired configuration. As noted above, one method molds the header110 separately and later bonds the header to the metallic devicecontainer 102. Another method molds the header 110 while in contact withthe metallic device container 102. In one example, a ratio of resin tohardener is approximately 2:1 by volume. In one example the mold ispreheated to approximately 50° C. prior to injection.

In one example a temperature of one or more portions of the epoxy israised prior to injecting the components into the mold. In one example,the epoxy is preheated to approximately 50° C. prior to injection.Raising a temperature of an epoxy component can reduce a viscosity ofthe component, thereby facilitating improved properties such asthroughput time and quality of the molded header (e.g. fewer air bubblesand better penetration into surface texture of the surface 114 of themetallic device container 102). In one example, one or more portions ofthe epoxy is injected at a pressure of less than 0.034 megapascals(MPa).

In one example the epoxy is cured at a temperature higher than roomtemperature (e.g. 25° C.). In one example the epoxy is cured atapproximately 50° C. In one example the epoxy is cured at approximately85° C. In one example the epoxy is cured at room temperature. In oneexample, more than one time and temperature are used to cure the epoxy.In one example components are held in a mold for a period of time at afirst temperature before a second heating phase that is used to completethe cure process. One example method includes heating in a mold atapproximately 50° C. for a period of time, then heating the mold toapproximately 85° C. to complete the cure process. In one example themethod includes holding the mold at approximately 50° C. forapproximately 40 minutes, then heating the mold to approximately 85° C.,and holding at 85° C. for approximately 10 minutes to complete the cureprocess. In one example, the first cure step includes placing the moldin an oven at approximately 50° C., and turning off the oven, allowingthe mold to slowly cool from approximately 50° C. to a lower temperatureat the end of 40 minutes. This slow cooling process during cure canprovide enhanced material properties such as a low concentration of airbubbles in the epoxy, and a high fracture toughness.

FIG. 2 shows a Fourier Transform Infrared spectroscopy (FTIR) spectra210 of an epoxy used in forming the header 110. In one example, theepoxy characterized by spectra 210 includes a number of desirableproperties, such as high modulus, high fracture toughness, highhardness, and high failure strength. In one example, the cured epoxyincludes a Shore D hardness between 75 and 90. In one example, the curedepoxy includes a tensile strength of approximately 55 MPa. In oneexample, the cured epoxy includes a glass transition temperature ofapproximately 70° C. The epoxy characterized by spectra 210 is alsosubstantially transparent. A transparent header 110 can be usefulbecause components such as contacts 112 can be visually inspected duringmanufacture and use of the IMD 100. In one example, the epoxy includesM-31CL provided by LOCTITE®. M-31CL is typically used as an adhesive,and is not commonly used for molding structural components.

FIG. 3A illustrates an embodiment of the surface 114 of the metallicdevice container 102, including a textured surface. In one example, asurface roughness of the surface 114 is characterized by opticalprofilometry techniques. White light interference patterns are analyzedto yield a number of roughness figures of merit, including surfaceaverage (S_(a)); surface root-mean-square (S_(q)); surface maximum(S_(max)); surface minimum (S_(min)); range (S_(y)); and a surface areascanned (S3A). FIG. 3B shows an example output of a surface roughnessscan of a textured surface 114.

In one example surface 120 includes an S_(q) between 3.05 micrometers(μm) and 10.2 μm. In one example surface 114 includes an S_(q) between3.81 μm and 8.89 μm. In one example surface 114 includes an S_(q)between 3.30 μm and 3.81 μm. Texturing the surface 114 prior toattachment or overmolding of the header 110 increases strength of theinterface between the header 110 and the metallic device container 102.

FIG. 3A shows a periodic pattern including a first linear feature 302and a second linear feature 304. The additional texture of features 302,304 can enhance adhesion at an interface between the surface 114 of themetallic device container 102 and the header 110. In one example, thesurface 114 of the metallic device container 102 is textured around acurved surface 305 at edges of the metallic device container 102. In oneexample, a high quality texture is provided on curved surfaces 305 ofthe metallic device container 102 by rotating the metallic devicecontainer 102 during surface processing to best expose the curvedsurface 305 to the processing media, such as blast particles, laserenergy, etc. In another example, the metallic device container 102 staysfixed, and the processing media source (blast particles, laser energy,etc.) rotates around an incident angle to provide a substantiallytangent incident angle to the curved surfaces 305.

FIG. 3C shows another example of a textured surface formed according toan example process. FIG. 3C illustrates another example texture thatexhibits one or more periodic patterns. A ridge 306 and a trough 308 areillustrated in the figure. In selected embodiments, more than oneperiodic pattern is included in a single textured surface. For example,a second periodic pattern is included in FIG. 3C, with a ridge 310 and atrough 312.

FIG. 3D shows another example of a textured surface formed according toan example process. In FIG. 3D, a number of particles 320 are formed,and adhered to the surface of the metal. The particles 320 can be usefulin later adhesion of an epoxy, or other thermoset header for a number ofreasons, including an undercut portion, where the particle 320 adheresto the metal surface, due to a substantially spherical shape of selectedparticles 320, adhering at tangent points of spheres. In one example thetextured surface as shown in FIG. 3D is formed by laser treatment.

The surface 114 can be textured in a variety of methods. For example,the surface 114 can be textured by dry surface blasting with particlessuch as aluminum oxide particles, laser treating the surface 114, orchemical etching the surface 114. In one embodiment, one or more ofthese texturing processes are used to texture the surface 114. Althougha number of example texturing methods are listed, other methods thatproduce a surface roughness in the desirable ranges are also consideredwithin the scope of the present disclosure.

In one example, the surface 114 is textured in a periodic pattern. Inone example, the periodic pattern includes a linear (e.g. hatched)pattern of ridges 304 and troughs 302 as shown in FIG. 3A. In oneexample, a scanned laser treatment provides the linear textured pattern.In some examples, the surface 114 is textured in a multidirectionalpattern. In further examples, the multidirectional pattern includes afirst pattern 314 and a second pattern 316. In some examples, one ormore of the patterns of the multidirectional pattern are etched. In someexamples, the first pattern 314 is disposed around a periphery of thesurface 114 of the metallic device container 102. In some examples, thefirst pattern 314 includes a pattern of ridges running substantiallyalong the periphery of the surface 114. In some examples, the firstpattern 314 is disposed at least partially along the curved surface 305of the metallic device container 102. The second pattern 316, in someexamples, includes a pattern of ridges disposed on the surface 114 ofthe metallic device container 102 within the first pattern 314, whereinthe first pattern 314 forms a border around the second pattern 316.Although the multidirectional pattern of FIG. 3A shows only the firstand second patterns 314, 316, it is contemplated that, in furtherexamples, the multidirectional pattern can include more than twopatterns. In other examples, the multidirectional pattern can includeportions of differing intensity, including, but not limited to, higheror lower ridges, more or fewer ridges or other pattern features per unitof area of the surface, more or less defined ridges or other patternfeatures, or a combination of these examples. It is noted that, in someexamples, the multidirectional pattern can include lines or ridges thatare substantially straight, wavy, or otherwise varied along its lengthor can include a pattern feature other than lines, such as dimples,bumps, or the like. Such examples of multidirectional patterns canlimit, reduce, or otherwise inhibit stress concentrations or defectpropagation of an overmolded header. For instance, in themultidirectional pattern of FIG. 3A, the first pattern 314 includingridges that run around the periphery of the surface 114 provides aboundary that can moderate a stress concentration from a deflectionforce crossing the boundary.

FIG. 4 shows a graph with a plot 402 of laser scan speed versus aresulting S_(q) value for the surface 114. The plot 402 of FIG. 4 isprovided using a 0.1 millimeter (mm) offset between scans of the laser,and a 0.068 mm diameter laser spot size.

FIG. 5 shows a graph of side load failure strength versus S_(q). A plot502 shows that side load strength increases with increasing values ofS_(q), with a high rate of change in strength achieved at S_(q) valuesbetween 120 and 150.

FIG. 6A shows a testing device 600 for measuring side load failurestrength. A clamp 602 is used to secure the metallic device container102, while the header 110 is pressed using a ram 604 along direction606. FIG. 6B shows an example of an IMD 100 after failure testing indevice 600. The header 110 is shown with a fracture 602. In the exampleshown, the fracture 602 is in the header 110 itself, rather than at thesurface 614 of the metallic device container 102, indicating that thebond strength between the header 110 and the metallic device container102 was higher than the strength of the header 110 in the bulk.

As discussed herein, failure mode in either the bulk, as shown in FIG.6B, or at an interface between the header 110 and the surface 114, canbe dependent on geometry of the metallic device container 102. Forexample, in extremely thin metallic device containers 102, the failuremode may change from the bulk of the header 110, to the interfacebetween the header 110 and the surface 114.

In contrast, in some embodiments when the metallic device container 102has a thickness between approximately 16 mm and 4 mm, a header 110 canfail in the bulk before failure at the interface between the header 110and the surface 114. In another embodiment, a header 110 can fail in thebulk before failure at the interface between the header 110 and thesurface 114 for configurations of metallic device container 102 withthicknesses between approximately 14 mm and 6 mm. Additionally, a header110 can fail in the bulk before failure at the interface between theheader 110 and the surface 114 for configurations of metallic devicecontainer 102 with thicknesses between approximately 12 mm and 8 mm.

FIG. 7 shows a graph of side load failure strength testing for a numberof header materials. Test specimens A, B, and C include S_(q) valuesbetween 120 and 150, with resulting side load failure strength betweenapproximately 0.334 kilonewtons (KN) and 0.489 KN. Test specimens A, B,and C include headers 110 formed from the epoxy characterized by theFTIR spectra 210 in FIG. 2. Test specimens D, E, F, G, and H includedifferent epoxy compositions. As can be seen from the graph in FIG. 7,the choice of epoxy and surface roughness combine to produce an IMD 100with higher side load failure strength (S_(q)) than other epoxymaterials.

Referring to FIGS. 8-12, an example IMD 800 is shown. In some examples,the IMD 800 includes a device container 802. The IMD 800, in someexamples, includes a header 810 attached to the device container 802.The header 810, in different examples, can be attached to the devicecontainer 802 in various ways, including molding the header 810 to thedevice container 802, for instance, as described herein. In someexamples, the header 810 can be formed from one or more of the materialsdescribed herein. In some examples, an adhesive can be used to attachthe header 810 to the device container 802, as described herein. In someexamples, the device container 802 can include a textured surface forattachment of the header 810 to the device container 802, as describedherein.

The header 810, in various examples, includes one or more electronicconnection features, such as, for instance, one or more bore holes 812.In the example shown, the header 810 includes three different types ofbore holes 812A, 812B, 812C. The one or more bore holes 812, in someexamples, can be used to couple to additional components, such as leads.In some examples, each of the one or more bore holes 812 includes one ormore electrical contacts 814 configured to electrically couple to one ormore leads or other components inserted within the bore hole 812. Invarious examples, the one or more electrical contacts 814 areelectrically coupled to one or more of the one or more electronicmodules within the device container 802. For instance, in some examples,the electrical contact 814 is coupled to a wire 806 disposed between theelectrical contact 814 and the one or more electronic modules. In anexample, the wire 806 passes through a feedthrough 804 of the devicecontainer 802 that is configured to allow one of more wires 806 to passinto the device container 802 while maintaining a sealed environmentwithin the device container 802.

The header 810, in some examples, includes a header core 820 and aheader shell 840 disposed around the header core 820. In furtherexamples, the header shell 840 is attached to the device container 802.In some examples, the header core 820 is formed separately from theheader shell 840 and/or the device container 802. In some examples, theheader core 820 and the header shell 840 are separately molded. Infurther examples, the header core 820 is molded and electrically coupledto the device container 802, and, thereafter, the header shell 840 ismolded around the header core 820 and the device container 802. In someexamples, molding the header shell 840 around the header core 820 andthe device container 802 affixes the header shell 840 directly to thedevice container 802, as described herein, and acts to retain the headercore 820 with respect to the device container 802. In some examples, theheader core 820 is formed from a first material and the header shell 840is formed from a second material, the first material being differentfrom the second material. In an example, the first material or thesecond material includes a polymer material. A polymer can provide anumber of desirable features, such as biocompatibility, strength,resilience, and ease of manufacturing. In some examples, the firstmaterial includes a thermoplastic material. In further examples, thefirst material includes one or more of polysulfone, polycarbonate,and/or polyurethane. In still further examples, the first materialincludes one or more of Isoplast and/or Tecothane. In some examples, thefirst material includes a thermoset material, such as, for instance,polyurethane. In some examples, the second material includes epoxy.

Forming the header core 820 separately from the header shell 840 and/ordevice container 802 is advantageous for many reasons including, but notlimited to: verifying bore hole geometry and orientation with respect tothe header core 820 and/or, ultimately, the device container 802;verifying location of the one or more electrical contacts 814; andproviding for routing control of the one or more wires 806.Additionally, in some examples, separately forming the header core 820can reduce losses in the event of a defect or other impropriety in theheader core 820. For instance, if a defect is discovered in a headercore, then that header core can be discarded prior to attachment withthe device container, the loss of which, in at least some circumstances,is considerably less than the loss if an entire IMD had to be discardeddue to the discovery of a defect with the header.

In some examples, the header 810 includes an identification tag 818,which, for instance, can include information relevant to theidentification of the IMD 800 and/or the patient within which the IMD800 is implanted. In some examples, the identification tag 818 isvisible in one or more imaging modalities, such as, for instance, x-ray,ultrasound, computed tomography, magnetic resonance imaging, or thelike. In an example, the identification tag 818 is configured to bex-ray readable. In an example, the identification tag includes tungsten.In some examples, the identification tag 818 can include a radiofrequency identification tag or can otherwise include informationaccessible using radio frequency interrogation.

Referring now to FIGS. 8, 9, and 11-13, the identification tag 818, invarious examples, is engaged or retained within a tag holder 822 of theheader core 820. The tag holder 822 can include an opening 824 sized andshaped to retain at least a portion of the identification tag 822 withinthe opening 824. In an example, the tag holder 822 is configured tomaintain the identification tag 818 in a specified position and locationwith respect to the IMD 800 to facilitate finding and reading theidentification tag 818, for instance, using an imaging device. In someexamples, the tag holder 822 maintains the location of theidentification tag 818 during molding of the header shell 840 over theheader core 820.

In some examples, the opening 824 is a slot 824A sized to accept theidentification tag 818 and frictionally retain the identification tag818 within the slot 824A. In further examples, the opening 824 includesa second portion 824B (FIGS. 11 and 13) in addition to the slot 824A,the second portion 824B being configured to facilitate overmolding ofthe header shell 840. That is, the second portion 824B allows materialto enter the opening 824 during overmolding of the header shell 840, forinstance, to get within one or more cutouts 818A in the identificationtag 818 disposed within the opening 824 and limit void spaces (i.e.,areas unfilled by mold material during overmolding of the header shell840) within the header shell 840 at the location of the one or morecutouts 818A. Such void spaces can lead to various molding problems ordefects, such as, for instance, delamination (i.e., separation) of theheader shell 840 with respect to the header core 820 and/or the devicecontainer 802. In some examples, the second portion 824B is a secondslot that extends substantially perpendicular to the slot 824A to form agenerally plus-shaped opening 824 when viewed from an end. In otherexamples, different opening shapes are contemplated, such as, forinstance, a single slot shape (for instance, just the slot 824A), anopening including one or both side walls being generally rounded (asubstantially elliptical opening, for instance), an opening includingone or both side walls being at least partially bowed-out, a T-shapedopening, or the like.

Referring to FIG. 14, in other examples, an identification tag 1418 caninclude a base 1419 configured to be retained by a header core. In anexample, the base 1419 includes a post 1419A extending from the base1419, the post 1419A configured to be engaged with or otherwise retainedby a tag holder (for instance, within a corresponding opening) of theheader core. In a further example, the post 1419A frictionally fitswithin the opening to retain the identification tag 1418 in a desiredposition during overmolding of a header shell. In further examples, thepost 1419A can include an indexing feature configured to position andmaintain the identification tag 1418 in a selected orientation withrespect to the header core. In some examples, the indexing featureincludes a shape to inhibit the post 1419A from rotating or otherwisebeing inserted improperly within the opening. For instance, the post1419A can include a generally cylindrical shaft with a flat surface or akey to correspond to a similar, complementary feature of the opening. Inother examples, the post 1419A can include an asymmetric shape oranother shape capable of being inserted and retained within acomplementary opening in a particular orientation.

In some examples, instead of or in addition to using an identificationtag similar to the example identification tags 818, 1418 describedherein, an identification tag can be printed on a portion of an IMD. Insome examples, the identification tag can be printed on a surface of aheader core. In other examples, the identification tag can be printed onanother portion of the IMD, such as, for instance, a surface of a devicecontainer and/or a component within the device container, such as abattery. In some examples, the identification tag can be printed using amaterial that is capable of being imaged using an imaging technique. Forinstance, in an example, the identification tag can be printed on aportion of the IMD using an ink or other material that is x-ray opaqueor otherwise visible using x-ray imaging, such that, when the IMD isx-ray imaged, the identification tag can be seen in the x-ray image. Inother examples, the printed identification tag can be configured to bevisible using other imaging techniques in addition to or instead ofusing x-ray imaging. In some examples, the identification tag is padprinted and/or tampoprinted onto a portion of the IMD.

Referring now to FIGS. 8-10 and 12, in some examples, the header core820 includes an antenna attachment feature 826 configured to locate,support, and/or position an antenna 808 with respect to the header core820 and, in turn, the IMD 800 and the patient within which the IMD 800is ultimately implanted. In some examples, the antenna attachmentfeature 826 is configured to maintain a substantially constant distancebetween the antenna 808 and the patient. In the example shown in thepresently-referenced figures, the antenna 808 is a substantiallyspiral-shaped antenna 808, and the antenna attachment feature 826 isshaped to accommodate such an antenna. In other examples, the antennaattachment feature can be differently shaped, sized, and/or configuredto accommodate differently-shaped antennas.

The antenna 808, in some examples, is engaged with the antennaattachment feature 826 and is electrically coupled with the electronicmodule within the device container 802. In some examples, a wire 806 isattached to the antenna 808 and is disposed between the antenna 808 andthe electronic module within the device container 802 to electricallycouple the antenna with the electronic module. In other examples, theantenna can be directly electrically coupled to the electronic moduleand can extend from the electronic module within the device container802 to the antenna attachment feature 826.

In some examples, the antenna attachment feature 826 is configured tolocate the antenna 808 in a selected position with respect to the headercore 820. The selected position, in various examples, allows for theantenna 808 to receive and/or send communication signals. In this way,the IMD 800 can be communicatively coupled with one or more deviceslocated either within or outside the patient. In the example shown inthe presently-referenced figures, the antenna 808 is disposed at a firstsurface of the header core 820 (the left side surface of the header core820, as shown in FIG. 8) and wraps around to adjacent surfaces of theheader core 820. The header shell 840, in some examples, is disposedaround the header core 820 and is attached to the device container, asdescribed herein. In further examples, the header shell 840 is alsodisposed around the antenna 808, such that the header shell 840 acts toat least partially retain the antenna 808 in the selected positionwithin the header shell 840.

The antenna attachment feature 826, in some examples, includes anabutment feature, such as a protrusion or a ridge 828, configured toretain the antenna 808 with respect to the antenna attachment feature826. In some examples, the abutment feature can include one or morepins, posts, or the like. In some examples, the ridge 828 is sized andpositioned on the antenna attachment feature 826 to abut the antenna 808and support the antenna 808 in the selected position with respect to theheader core 820. In some examples, the antenna 808 rests on the ridge828. In some examples, the ridge 828 positively engages the antenna 808,for instance, with a retention feature configured to grip at least aportion of the antenna 808. Examples of such a retention feature includea lip, protrusion, or other structure extending from the ridge 828 toform a slot within which a portion of the antenna 808 can be retained.In further examples, the retention feature is configured to frictionallyretain at least the portion of the antenna 808. The ridge 828, invarious examples, is sized and shaped to fit between portions 808A, 808B(FIG. 9) of the antenna 808. In an example, the portions 808A, 808B ofthe antenna 808 are configured to frictionally engage the ridge 828.

In some examples, the antenna attachment feature 826 includes more thanone ridge 828. The ridges 828, in some examples, are spaced and locatedto accommodate the antenna 808 between the ridges 828. For instance, aportion 808C of the antenna 808 is shown in FIG. 8 disposed between tworidges 828A, 828B. In a further example, the ridges 828A, 828B arespaced to provide a frictional engagement with the portion 808A of theantenna 808. In an example, the one or more of the ridges 828 of theantenna attachment feature 826 are disposed between portions 808A, 808Bof the antenna 808 and are configured to maintain spacing between theportions 808A, 808B of the antenna 808. In further examples, the one ormore ridges 828 are configured to maintain spacing between the antenna808 and other components, such as, for instance, wires 806, electricalcontacts 814, the device container 802, or the like. In this way, theone or more ridges 828 act to inhibit shorts between the antenna 808 andother components of the IMD 800.

In some examples, the ridges 828 are disposed on multiple sides of theantenna attachment feature 826. For instance, in the example shown inthe referenced figures, the antenna 808 wraps around three sides of theantenna attachment feature 826, with one or more ridges 828 on each ofthe three sides of the antenna attachment feature 826 to support thevarious sides of the antenna 808 wrapping around the antenna attachmentfeature 826. In other examples, the antenna attachment feature 826includes different shapes and configurations of ridges or otherprotrusions to accommodate and support differently sized and/or shapedantennas. In various examples, the antenna attachment feature 826 isconfigured to inhibit mold defects during overmolding of the headershell 840. For instance, one or more various aspects of the antennaattachment feature 826 are shaped and configured to allow the moldmaterial to flow around the one or more aspects of the antennaattachment feature 826 during the overmolding of the header shell 840with little to no turbulence, collection of bubbles, formation of voidspaces, or other defects which could give rise to problems with themolded header shell 840, such as, for instance, delamination from theheader core 820.

Referring to FIG. 15, in some examples, an antenna attachment feature1526 can include an antenna attachment portion 1527 configured todetachably engage with a header core. The antenna attachment portion1527 can be detachably engaged to the header core in various ways,including complementary engagement features disposed on the antennaattachment portion 1527 and the header core, like a tab-and-slotconfiguration or a pin-and-hole configuration, for instance. In furtherexamples, the header core and the antenna attachment portion 1527 caninclude mating snap-together features or mating slide-together features.In still further examples, adhesive can be used to engage the antennaattachment portion 1527 with the header core.

The antenna attachment feature 1526, in various examples, includes oneor more abutment features, such as protrusions, pins, posts, and/orridges 1528 configured to retain an antenna 1508 with respect to theantenna attachment feature 1526. In some examples, the one or moreridges 1528 are similar to the ridges 828 described herein. In variousexamples, the antenna attachment feature 1526 is configured to inhibitmold defects during overmolding of the header shell. For instance, oneor more various aspects of the antenna attachment feature 1526 areshaped and configured to allow the mold material to flow around the oneor more aspects of the antenna attachment feature 1526 during theovermolding of the header shell with little to no turbulence, collectionof bubbles, formation of void spaces, or other defects which could giverise to problems with the molded header shell, such as, for instance,delamination from the header core.

Referring to FIG. 16, in some examples, an IMD 1600 includes a header1610 attached to a device container 1602, the header 1610 including aheader shell 1640 disposed around a header core 1620. In some examples,the header core 1620 includes an antenna attachment feature 1626configured to locate and/or support an antenna 1608 in a selectedposition with respect to the header core 1620. In the example shown inthe presently-referenced figure, the antenna 1608 is a wire member thatextends from the device container 1602, extends along one side of theheader core 1620, wraps around a front of the header core 1620, andextends along the other side of the header core 1620. In furtherexamples, the header shell 1640 is also disposed around the antenna1608, such that the header shell 1640 acts to at least partially retainthe antenna 1608 in the selected position within the header shell 1640.

In some examples, the antenna attachment feature 1626 includes a channel1627 sized to accept the antenna 1608 within the channel 1627. In someexamples, the channel 1627 can extend along one or more sides of theheader core 1620, depending on the desired configuration, position,and/or location of the antenna 1608 with respect to the header core1620. In further examples, the channel 1627 can extend continuously orcan be broken into segments on one or more sides of the header core1620. The antenna attachment feature 1626, in some examples, isintegrally formed in the header core 1620. For instance, the antennaattachment feature 1626 can be molded and/or machined into the headercore 1620. In further examples, the antenna attachment feature 1626 canbe affixed to the header core 1620 using an adhesive, for instance. Instill further examples, the antenna attachment feature 1626 can beengaged with the header core 1620 using complementary engagementfeatures or the like.

The antenna attachment feature 1626, in some examples, includes one ormore retention features 1628 configured to retain the antenna 1608within the channel 1627. In some examples, the retention feature 1628includes a protrusion, lip, or other such structure extending from aside of the channel 1627 to at least partially capture the antenna 1608within the channel 1627. The one or more retention features 1628 can bedisposed at one or more various locations along the channel 1627. Inthis way, the antenna 1608 can be maintained within the channel 1627 tolocate and position the antenna 1608 in a selected position with respectto the header core 1620. In further examples, the one or more retentionfeatures 1628 and the channel 1627 of the antenna attachment feature1626 maintain the antenna 1608 in the selected position during formingof the header shell 1640 around the header core 1620. In still furtherexamples, the channel 1627 and the one or more retention features 1628are formed to facilitate molding of the header shell 1640 around and/orwithin the antenna attachment feature 1626 while inhibiting void spacesin molding, which could lead to mold problems, such as delamination ofthe header shell 1640 from the header core 1620.

In some examples, the channel 1627 can be configured to accept theantenna 1608 within the channel 1627, and, instead of or in addition tousing one or more retention features 1628 to retain the antenna 1608within the channel 1627, the channel 1627 can be configured to allowcrimping of one or more portions of the channel 1627 to retain theantenna 1608 within the channel 1627. For instance, a portion of thechannel 1627 can include walls that extend from a surface of the headercore 1620 to allow a crimping tool, for instance, to engage with thewalls and crimp the walls of the channel 1627 to retain the antenna 1608within the channel 1627. In other examples, the channel 1627 includesone or more portions configured to allow crimping and/or deformation ofthe one or more portions for retention of the antenna 1608 within thechannel 1627.

In some examples, instead of or in addition to using an antenna similarto the example antennas 808, 1508, 1608 described above, an antenna canbe printed on a portion of an IMD. In some examples, the antenna can beprinted on a surface of a header core. In other examples, the antennacan be printed on another portion of the IMD. In some examples, theantenna can be printed using a conductive material or combination ofmaterials. In an example, the antenna is printed in a manner configuredto allow formation of the antenna to a particular thickness. Forinstance, the antenna can be formed to a thickness of approximately 10micrometers. In other examples, the antenna can be formed to a thicknessof greater than or less than 10 micrometers, provided the antenna iscapable of functioning as described herein.

In further examples, the header core 1620 can include one or morematerial relief features 1635 at locations, such as at one or morecavities 1634 of the header core 1620. In some examples, the materialrelief feature 1635 allows for a reduced likelihood of delaminationoccurring between the header core 1620 and the header shell 1640. Forinstance, the relief feature 1635 can be positioned at a location wheredelamination is more likely to occur to provide a safeguard againstdelamination. In some examples, the relief feature 1635 can include aridge or other protrusion that acts to provide a break in the continuityof a surface and, therefore, provide a barrier against continueddelamination. For example, if delamination begins at a location, suchdelamination will continue across a surface until a break in the surface(like a ridge, for instance) is encountered, at which point delaminationwill be contained. As such, in some examples, the relief feature 1635 ofthe header core 1620 can include a ridge, protrusion, or other relieffeature at or near one or more locations in the header core 1620 whichhave an increased likelihood of being a nucleation site of delamination,such as around the cavity 1634. In further examples, one or morelocations of the header core 1620 other than or in addition to the oneor more cavities 1634 include a relief feature. In still furtherexamples, the one or more relief features 1635 are configured to allowsubstantially free flow of mold material and escape of air duringovermolding of the header shell 1640, thereby allowing for a reducednumber of mold defects (e.g., void spaces and the like) in the headershell 1640.

In some examples, the header 1610 can be formed from one or more of thematerials described herein. In some examples, an adhesive can be used toattach the header 1610 to the device container 1602, as describedherein. In some examples, the device container 1602 can include atextured surface for attachment of the header 1610 to the devicecontainer 1602, as described herein.

Referring to FIG. 17, in some examples, a header core 1720 includes anantenna attachment feature 1726 configured to locate and/or support anantenna in a selected position with respect to the header core 1720. Insome examples, the antenna attachment feature 1726 includes a channel1727 configured to at least partially receive the antenna. In someexamples, the channel 1727 can extend along one or more sides of theheader core 1720, depending on the desired configuration, position,and/or location of the antenna with respect to the header core 1720. Infurther examples, the channel 1727 can extend continuously or can bebroken into segments on one or more sides of the header core 1720. Theantenna attachment feature 1726, in some examples, is integrally formedin the header core 1720. For instance, the antenna attachment feature1726 can be molded and/or machined into the header core 1720. In furtherexamples, the antenna attachment feature 1726 can be affixed to theheader core 1720 using an adhesive, for instance. In still furtherexamples, the antenna attachment feature 1726 can be engaged with theheader core 1720 using complementary engagement features or the like.

In some examples, the antenna attachment feature 1726 includes one ormore retention features 1728 configured to retain the antenna within thechannel 1727. In some examples, the retention feature 1728 includes anarrowed portion of the channel 1727 configured to frictionally engageat least a portion of the antenna. The one or more retention features1728 can be disposed at one or more various locations along the channel1727. In this way, the antenna can be maintained within the channel 1727to locate and position the antenna in a selected position with respectto the header core 1720. In further examples, the one or more retentionfeatures 1728 and the channel 1727 of the antenna attachment feature1726 maintain the antenna in the selected position during forming of aheader shell around the header core 1720. In still further examples, thechannel 1727 and the one or more retention features 1728 are formed tofacilitate molding of the header shell around and/or within the antennaattachment feature 1726 while inhibiting void spaces in molding, whichcould lead to mold problems, such as delamination of the header shellfrom the header core 1720.

Referring to FIG. 18, in some examples, an IMD 1800 includes a header1810 attached to a device container 1802, the header 1810 including aheader shell 1840 disposed around a header core 1820. In some examples,the header core 1820 includes one or more locating features 1830 forlocating and/or routing one or more wires 1806 of the IMD 1800. In someexamples, the one or more locating features 1830 act to maintain spacingbetween the one or more wires 1806 and other wires 1806, electricalcontacts 1814, and other conductive components of the IMD 1800 to limitthe likelihood of shorting between the one or more wires 1806 and otherwires 1806, electrical contacts 1814, and other conductive components ofthe IMD 1800. In some examples, the one or more locating features 1830are protrusions extending outwardly from the header core 1820. In theexample shown in FIG. 18, the locating features 1830 are substantiallycylindrical protrusions positioned in pairs to accommodate the wires1806 therebetween to limit movement of the wires 1806 and lessen thelikelihood of shorting of the wires 1806. In further examples, the oneor more locating features 1830 can be used to facilitate inspection ofthe one or more wires 1806. That is, the locating features 1830 allowone to see where the wire 1806 is supposed to be located and tofacilitate noticing whether a wire is missing or is otherwise misroutedwith respect to the header core 1820.

In various examples, the one or more wires 1806 can be bent prior to theheader core 1820 being placed in position with respect to the devicecontainer 1802. For instance, prior to affixing the header core 1820 tothe device container 1802, each of the one or more wires 1806 can bebent and/or manipulated into a selected configuration, such that the oneor more wires 1806 are substantially in place with respect to connectionlocations on the header core 1820 so that, once the header core 1820 isput in position, the one or more wires 1806 are substantially alignedwith the corresponding one or more connection points (for instance, theone or more electrical contacts 1814). The one or more wires 1806 canthen be affixed to the corresponding one or more electrical contacts1814, for instance, using spot welding.

In some examples, referring briefly to FIGS. 32-34, a template 3210 anda bending tool 3220 can be used to manually bend the one or more wires1806 into selected positions for attachment to the header core 1820. Thetemplate 3210, in some examples, is engagable with the device container1802 such that the one or more wires 1806 extend outwardly from thetemplate 3210. The template 3210, in some examples, includes features3212 (such as, for instance, ridges, channels, or the like) tofacilitate bending of the one or more wires 1806 into the selectedconfigurations. The bending tool 3220, in some examples, includes ahandle 3222 with a bending tube 3224 extending outwardly from the handle3222. The bending tube 3224, in some examples, is configured to fit overthe wire 1806 (for instance, the wire 1806 can fit inside the bendingtube 3224) allowing a user to manipulate the bending tool 3220 andachieve a bend in the wire 1806. Once the one or more wires 1806 arebent into the selected configurations, the template 3210 can be removedfrom the device container 1802, leaving the one or more wires 1806 bentinto the selected configurations. In some examples, the template 3210 isseparable (for instance, the template 3210 can include two or moreseparable portions 3210A, 3210B) to allow the template 3210 to beremoved from the device container 1802 without affecting the one or morebends of the one or more wires 1806. In other examples, the one or morewires 1806 can be bent using an automated process, for instance, using arobotic arm preprogrammed to bend the one or more wires 1806 in theselected one or more configurations.

Referring again to FIG. 18, in other examples, the header core 1820 canbe placed in position on the device container 1802 and the one or morewires 1806 can be bent into position using the locating features 1830 ofthe header core 1820 as bending guides. That is, the wire 1806 can bebent to pass through or around the appropriate locating features 1830 tothe electrical contact 1814 of the header core 1820.

In some examples, the header 1810 can be formed from one or more of thematerials described herein. In some examples, an adhesive can be used toattach the header 1810 to the device container 1802, as describedherein. In some examples, the device container 1802 can include atextured surface for attachment of the header 1810 to the devicecontainer 1802, as described herein.

Referring to FIG. 19, a header core 1920, in some examples, includes oneor more locating features 1930 generally similar to the locatingfeatures 1830 described herein. In some examples, the one or morelocating features 1930 can include generally prismatic protrusions 1930Aand/or generally cylindrical protrusions 1930B, each extending outwardlyfrom the header core 1920. In some examples, the prismatic locatingfeatures 1930A can be spaced in proximity to one another and can beconfigured to accommodate a wire therebetween, and the cylindricallocating features 1930B can be positioned on the header core 1920 tolocate bends in the wire and/or to constrain the wire from migratinginto contact with another wire, an improper electrical contact, or thelike.

Referring to FIGS. 20 and 21, in some examples, a mold apparatus 2000 isconfigured for molding a header shell around or otherwise to a headercore and/or a device container of an IMD. In some examples, the moldapparatus 2000 includes a mold cavity 2002 sized to accommodate theheader core within the mold cavity 2002 to allow overmolding of theheader shell. In further examples, the mold cavity 2002 is sized toaccommodate the header core and at least a portion of the devicecontainer within the mold cavity 2002 to allow overmolding of the headershell. In some examples, a partially-assembled IMD (including the headercore and the device container with electrical connections betweencomponents of the header core and one or more modules within the devicecontainer) is inserted within the mold cavity 2002 of the mold apparatus2000 and the mold apparatus 2000 is closed around thepartially-assembled IMD. In some examples, the mold apparatus 2000includes a first portion 2000A and a second portion 2000B joinedtogether with a hinge 2004 to allow the first and second portions 2000A,2000B to be closed for molding of the header shell and opened forremoval of the molded IMD and insertion of another partially-assembledIMD. In other examples, other mold apparatuses having differentconfigurations are contemplated, including mold apparatuses with morethan two portions and/or mold apparatuses having differentopening/closing configurations, provided the mold apparatuses arecapable of molding the header shell around the header core and attachingthe header shell to the device container.

In some examples, the mold apparatus 2000 includes a fill tube or port2008 configured to allow insertion of mold material within the moldcavity 2002. In some examples, the fill tube 2008 includes an opening2008A into the mold cavity 2002 at a bottom of the mold cavity 2002 toallow for filling of the mold cavity 2002 from the bottom. In furtherexamples, the location of the opening 2008A of the fill tube 2008 allowsfor low-pressure injection molding of the header shell. In someexamples, the location of the opening 2008A of the fill tube 2008 isdisposed at a location on the header displaced from an interface betweenthe header and the device container of the IMD. By doing so, stressconcentrations (for instance, stress concentrations caused by removal ofa sprue or flashing) can be limited at the interface between the headerand the device container of the IMD. Such stress concentrations at theinterface between the header and the device container of the IMD canlead, in some examples, to premature failure of the header, such as, forinstance, at least partial separation of the header from the devicecontainer.

In some examples, the mold apparatus 2000 includes a vent tube or port2010 configured to allow escape of air from within the mold cavity 2002during filling of the mold cavity 2002 with the mold material. In someexamples, the vent tube 2010 is disposed at a top of the mold cavity2002 to allow for venting of substantially all the air from within themold cavity 2002. In further examples, the location of the vent tube2010 is disposed at a location on the header displaced from an interfacebetween the header and the device container of the IMD. By doing so,stress concentrations (for instance, stress concentrations caused byremoval of a sprue or flashing) can be limited at the interface betweenthe header and the device container of the IMD. Such stressconcentrations at the interface between the header and the devicecontainer of the IMD can lead, in some examples, to premature failure ofthe header, such as, for instance, at least partial separation of theheader from the device container. In some examples, the vent tube 2010is at a location slightly displaced from the interface between theheader and the device container, such that substantially all the air ofthe mold cavity 2002 can escape during filling of the mold cavity 2002while, at the same time, allowing for displacement of the sprue orflashing from the interface between the header and the device containerso that removal of the sprue or flashing from the header will lesslikely result in stress concentrations at the interface between theheader and the device container.

In some examples, the mold apparatus 2000 includes a heating system toallow heating of the mold cavity 2002. After inserting the mold materialwithin the mold cavity 2002, the mold material can be cured by heatingthe mold cavity 2002. Such heating of the mold cavity 2002 and curing ofthe mold material can increase quality of the overmolded header shelland/or decrease the likelihood of delamination of the header shell fromthe header core. For instance, curing of the mold material can cause anadhesion layer to relatively quickly form between the mold material ofthe header shell and the header core. Such formation of the adhesionlayer creates increased adhesion between the header shell and the headercore and decreases the likelihood of subsequent delamination of theheader shell from the header core.

In some examples, the mold apparatus 2000 includes a high conductivitychannel 2006 and a heating system to heat the high conductivity channel2006. The high conductivity channel 2006, in some examples, extendsproximate the mold cavity 2002 and is capable of imparting heat to themold cavity 2002 and, in turn, to the mold material within the moldcavity 2002. In further examples, the high conductivity channel 2006 isin contact with the mold cavity 2002 (for instance, an outer surface ofthe mold cavity 2002), to enable the high conductivity channel 2006 toefficiently transfer heat to the mold cavity 2002 and the mold materialwithin the mold cavity 2002. In some examples, the remainder of the IMDwithin the mold apparatus 2000 (for instance, the device container) ismaintained at a lower temperature as compared to the mold materialduring curing of the mold material. The electronic modules within thedevice container can be less tolerant to heat and can be damaged byexcessive and/or prolonged heat. Thus, it can be desirable to maintainthe device container at a decreased temperature as compared to the highconductivity channel 2006 and/or the mold cavity 2002 during curing ofthe mold material within the mold cavity 2002. In some examples, thetemperature of the device container is maintained substantially at oraround an ambient temperature during heating of the mold cavity 2002. Insome examples, the temperature during curing of the mold material iswithin the range of 30° C. to 85° C. In some examples, a cure phase canbe achieved with a temperature ramp and decay cycle with a starttemperature and an end temperature within the range of 30° C. to 85° C.For instance, the cure phase can begin at a start temperature at orabove 30° C., ramp up to an end temperature within a range above 30° C.and at or below 85° C., and then decay to a temperature less than theend temperature, at which point the IMD can be removed from the moldapparatus 2000.

Curing times can vary for many different reasons. For instance, curingtimes can vary based on the mold material being used to form the headershell, the material(s) used to form the header core, environmentalconditions of the mold apparatus 2000 (e.g., temperature, humidity,pressure, and the like), curing temperature, and resilience of thecomponents of the IMD to high temperatures, for example. In someexamples, the curing time for the mold apparatus 2000 and IMDconfiguration is within the range of about ten to thirty minutes. Inother examples, the curing time can be more than 30 minutes or less thanten minutes.

In various examples, upon completion of the desired time of curing, theIMD can be removed from the mold apparatus 2000 for inspection and/orfinal processing of the IMD. For instance, various aspects of themolding process can leave flashing or other molding residue. Duringfinal processing, the flashing or residue can be removed, for instance,from an exterior of the header shell, within bores of the header, withinor around seal plug areas, in an interface area between the header andthe device container, within suture holes, and the like.

Referring to FIGS. 35-37, in some examples, a mold apparatus 3500 isconfigured for molding a header shell 3584 around or otherwise to aheader core 3586 and/or a device container 3582 of an IMD 3580. In someexamples, the mold apparatus 3500 includes a mold cavity 3502 sized toaccommodate the header core 3586 within the mold cavity 3502 to allowovermolding of the header shell 3584. In further examples, the moldcavity 3502 is sized to accommodate the header core 3584 and at least aportion of the device container 3582 within the mold cavity 3502 toallow overmolding of the header shell 3584. In some examples, apartially-assembled IMD (including the header core 3586 and the devicecontainer 3582 with electrical connections between components of theheader core 3586 and one or more modules within the device container3582) is inserted within the mold cavity 3502 of the mold apparatus 3500and the mold apparatus 3500 is closed around the partially-assembledIMD. In some examples, the mold apparatus 3500 includes a first portion3500A and a second portion joined together with a hinge, in a mannersimilar to that described herein and shown in FIGS. 20 and 21, to allowthe first portion 3500A and the second portion to be closed for moldingof the header shell 3584 and opened for removal of the molded IMD 3580and insertion of another partially-assembled IMD. In other examples,other mold apparatuses having different configurations are contemplated,including mold apparatuses with more than two portions and/or moldapparatuses having different opening/closing configurations, providedthe mold apparatuses are capable of molding the header shell around theheader core and attaching the header shell to the device container.

In some examples, the mold apparatus 3500 includes a block 3520configured to reduce if not eliminate flashing from occurring proximateto one or more bore holes of the header shell 3584. Flashing can occurat junctions between mold pieces. That is, a space present between moldpieces and accessible from the mold cavity can be susceptible toincursion of mold material during the molding process, which, whencured, forms flashing on the molded item. This flashing can often beremoved in post processing, thus adding at least an additional step tothe manufacturing of the molded item and increasing time and/or cost ofmanufacturing. In the manufacturing of the IMD 3580, in some examples,flashing present at or proximate to the one or more bore holes of theheader shell 3584 can present issues with insertion of one or more leads(or other devices) within the one or more bore holes, such as improperor insufficient engagement of the lead within the bore hole, forinstance. Such flashing can generally be removed during post processing,but, as stated, the removal adds time and/or cost to the process. Inother examples, removal of flashing from the one or more bore holes canbe difficult due to the geometry of the area around the one or more boreholes and/or due to contaminants from the removal process potentiallyentering the one or more bore holes of the header shell 3584. For atleast this reason, in some examples, maintaining mold junctions (orother mold features that can give rise to flashing) spaced from the oneor more bore holes of the header shell 3584 is contemplated.

In some examples, the block 3520 is maintained within the mold apparatus3500 during overmolding of the header shell 3584 to displace potentialflashing away from the one or more bore holes of the header shell 3584.In some examples, the block 3520 includes one or more pins 3522configured to fit within a corresponding one or more bore hole portionsof the header core 3586 to inhibit mold material from entering the oneor more bore hole portions of the header core 3586 and to form theremainder of the one or more bore holes of the header shell 3584. Insome examples, the block 3520 includes a flange 3524 or other structureto engage within at least one of the first portion 3500A or the secondportion of the mold apparatus 3500 to define the mold cavity 3502 duringthe molding process. In various examples, the block 3520 includes asurface 3526 sized, shaped, or otherwise configured to displacepotential flashing away from the one or more bore holes of the headershell 3584 to a location of the header shell 3584 where the potentialflashing is not likely to inhibit engagement of leads or other deviceswithin the one or more bore holes. In the example, shown in FIG. 37, thesurface 3526 is generally an elongated, flattened ellipse sized todisplace potential flashing to a perimeter of the surface 3526, which isdisplaced from the bore holes of the header shell 3584 formed by thepins 3522 of the block 3520 during the molding process. In an example,if no block were used and two mold portions with a junction along acenter line of the header shell were used, flashing would likely resultat the junction between the mold portions, which would be along a centerline of each of the one or more bore holes of the header shell. By usingthe block 3520 within the mold apparatus 3500, one or more junctionlocations of the mold apparatus 3500 can be moved away from the one ormore bore holes of the header shell 3584 to a location on the headershell 3584 where, for instance, resulting flashing does not adverselyaffect engagement of leads or other devices within the one or more boreholes of the header shell 3584. In addition, the resulting flashing canbe relatively easily removed from the header shell 3584 after molding ofthe header shell 3584 as compared to the removal of flashing from in andaround more complex structures or geometries of the header shell, suchas the one or more bore holes.

In some examples, use of the block 3520 with the mold apparatus 3500 canallow for more stable junctions and/or sealing surfaces betweencomponents of the mold apparatus 3500 to further limit flashingoccurring during molding. That is, the larger surface areas of thejunctions between the first portion 3500A, the second portion, and theblock 3520 can allow for a tighter, more stable junction between thecomponents of the mold apparatus 3500 than would be achievable using,for instance, a two-component mold apparatus with relatively littlesurface area between bore hole locations in such a mold apparatus. Inthis way, the mold apparatus 3500 can inhibit formation of flashing ordisplace potential flashing away from the one or more bore holes of theheader shell 3584 during overmolding of the header shell 3584 around theheader core 3586.

In some examples, the mold apparatus 3500 can include a fill tube orport 3508 configured to allow insertion of mold material within the moldcavity 3502. In some examples, the fill tube 3508 includes an opening3508A into the mold cavity 3502 at a bottom of the mold cavity 3502 toallow for filling of the mold cavity 3502 from the bottom (whenpositioned in a molding configuration, similar, for instance to thatshown in the examples of FIGS. 20 and 21). In further examples, thelocation of the opening 3508A of the fill tube 3508 can allow forlow-pressure injection molding of the header shell. In some examples,the location of the opening 3508A of the fill tube 3508 is disposed at alocation on the header shell 3584 displaced from an interface betweenthe header shell 3584 and the device container 3582 of the IMD 3580. Bydoing so, stress concentrations (e.g., stress concentrations caused byremoval of a sprue or flashing) can be limited at the interface betweenthe header shell 3584 and the device container 3582 of the IMD 3580.Such stress concentrations at the interface between the header shell3584 and the device container 3582 of the IMD 3580 can lead to prematurefailure of the header shell 3584, such as at least partial separation ofthe header shell 3584 from the device container 3582.

In some examples, the mold apparatus 3500 includes a vent tube or port3510 configured to allow air to escape from within the mold cavity 3502during filling of the mold cavity 3502 with the mold material. In someexamples, the vent tube 3510 is disposed at a top of the mold cavity3502 to allow for venting of substantially all the air from within themold cavity 3502 (when positioned in a molding configuration, similar,for instance to that shown in the examples of FIGS. 20 and 21). Infurther examples, the location of the vent tube 3510 is disposed at alocation on the header shell 3584 displaced from an interface betweenthe header shell 3584 and the device container 3582 of the IMD 3580. Bydoing so, stress concentrations can be limited at the interface betweenthe header shell 3584 and the device container 3582 of the IMD 3580, asstated herein. In some examples, the vent tube 3510 can be at a locationslightly displaced from the interface between the header shell 3584 andthe device container 3582 such that substantially all the air of themold cavity 3502 can escape during filling of the mold cavity 3502 whileat the same time allowing for displacement of the sprue or flashing fromthe interface between the header shell 3584 and the device container3582. The vent tube 3510 displacement can enable removal of the sprue orflashing from the header shell 3584 that is less likely to result instress concentrations at the interface between the header shell 3584 andthe device container 3582.

Referring to FIG. 22, in some examples, an IMD 2200 includes a header2210 including a header core 2220 and a header shell 2240 disposedaround the header core 2220. In various examples, the header 2210includes one or more bore holes 2212. In the example shown in FIG. 22,the header 2210 includes three bore holes 2212A, 2212B, 2212C. In otherexamples, however, the header can include more or fewer than three boreholes, depending on the intended application for the IMD. In someexamples, as described herein, the header core 2220 can be formed firstand then attached to the device container 2202 by molding the headershell 2240 around the header core 2220 and to the device container 2202.In some examples, the header 2210 can be formed from one or more of thematerials described herein. In some examples, an adhesive can be used toattach the header 2210 to the device container 2202, as describedherein. In some examples, the device container 2202 can include atextured surface for attachment of the header 2210 to the devicecontainer 2202, as described herein.

In some examples, the header core 2220 includes one or more bore holeportions 2232 formed within the header core 2220. The one or more borehole portions 2232, in various examples, correspond to the number ofbore holes 2212 of the header 2210. The bore hole portions 2232 can beformed during molding of the header core 2220, or formed by machining ofthe header core 2220.

In some examples, the header core 2220 includes one or more cavities2234 configured to allow insertion of components (e.g., electronicconnection features) within or otherwise proximate to the one or morebore hole portions 2232. Such components can include, but are notlimited to, a connector block, a seal ring, a tip connector, or thelike. In various examples, the cavity 2234 can be formed through a sideof the header core 2220 and intersect the bore hole portion 2232, sothat a component can be inserted into the cavity 2234 from the side ofthe header core 2220 and be placed in position within the bore holeportion 2232. Alternatively, some components can be placed through thebore hole portion 2232 and located in position within the header core2220. In this way, the header core 2220 can be formed to allow preciselocation of the components within the one or more bore hole portions2232 of the header core 2220. As such, in some examples, the componentscan be precisely located within the header core 2220 after formation ofthe header core 2220 and do not need to be molded into place within theheader core, for instance, using a mandrel to locate the components withrespect to each other and/or the header core. In some examples, theheader core 2220 includes at least two components or electronicconnection features disposed within the bore hole portion 2232, whereinthe header core 2220 is configured to allow location of the at least twocomponents or electronic connection features in a selected configurationwithin the bore hole portion 2232. For instance, the two components orelectronic connection features can be located a selected distance apartusing one or more of the cavities 2234 and/or the one or more bore holeportions 2232 of the header core 2220 after the header core 2220 hasbeen formed and do not require molding of the header core around thecomponents disposed on a mandrel.

The one or more bore hole portions 2232 can be inspected to confirmproper geometry, location with respect to other bore hole portions 2232,and/or location within the head core 2220. Once some or all of thecomponents are located within the header core 2220, the components ofthe header core 2220 can be tested to ensure proper placement within thebore hole portions 2232 and/or proper conductive functioning. By formingthe bore hole portions 2232 prior to connection of the header 2210 withthe device container 2202, the header core 2220 and the bore holeportions 2232 can be tested and/or inspected prior to attachment of theheader core 2220 to the device container 2202. In some examples, theheader core 2220 is formed to accept two or more components (such aselectronic connection features, for instance) within cavities 2234and/or bore hole portions 2232, and the locations of the components withrespect to one another and with respect to other features of the headercore 2220 can be inspected, tested, or otherwise viewed prior toattachment of the header core 2220 to the device container 2202. Asdescribed herein, enabling testing and/or inspection of the header core2220 allows defective header cores 2220 to be fixed or discarded priorto attachment with the device container 2202, thereby limiting lossesassociated with defective headers.

In some examples, components within the one or more bore hole portions2232 and/or cavities 2234 can be sealed within the header core 2220prior to overmolding of the header shell 2240 and/or connection with thedevice container 2202. Sealing of such components within the header core2220 can inhibit mold material infiltrating the one or more bore holeportions 2232 between the header core 2220 and the components duringovermolding of the header shell 2240.

In some examples, sealing can be achieved by using a sealant or abonding agent between the component and the header core 2220. However,use of the sealant or bonding agent introduces a further material to themanufacturing of the header core 2220. In some examples, the sealant orbonding agent can include an adhesive, such as a medical adhesive. Insome examples, the sealant or bonding agent can include one or more ofan epoxy, an acrylic, or a polymer, such as, for instance, ahot-dispense polyurethane. In some examples, the sealant or bondingagent can include one or more of a two-part epoxy and a cured epoxy. Insome examples, the sealant or bonding agent can include a cured urethaneacrylic. In some examples, the cured urethane acrylic and/or the curedepoxy can be cured using ultraviolet to visible light.

In some examples, a recess is formed around each of the one or morecavities 2234 configured to allow application of the sealant or bondingagent around the one or more components. The sealant or bonding agentcan have a viscosity that allows the sealant or binding agent to beapplied to the desired one or more cavities 2234 and/or components butinhibits the sealant or bonding agent from seeping between the componentand the cavity 2234 and entering into the bore hole portion 2232.

In other examples, a thermal process can be used to seal the componentwithin the header core 2220. For instance, in some examples, heating ofthe header core 2220 including the one or more components installedwithin the header core 2220 can slightly melt the material of the headercore 2220 around the one or more components, causing the melted materialof the header core 2220 to adhere to the one or more components. Theheader core 2220 can then cool, solidifying the melted material aroundthe one or more components and thereby sealing the one or morecomponents within the header core 2220. In some examples, such heatingof the header core 2220 can be accomplished by induction heating, laserheating, microwave heating, or radiant heating. In still other examples,such heating of the header core 2220 can be accomplished by directheating, such as, for instance, applying a heating element to thecomponent to heat the component and slightly melt the material aroundthe component.

In some examples, the header core 2220 can be formed of polyurethane,which can be fused to the one or more components using such heatingtechniques described herein. For example, a ten to fifteen second pulseof induction, laser, or other heating can effectively close at leastsome, if not all, of the gaps present between the header core 2220 andthe one or more components. Such heating techniques may also be employedfor header cores 2220 formed from materials other than polyurethane inorder to fuse, seal, or otherwise bond the one or more components withinthe header core 2220. However, heat pulse times for other materials canvary in order to substantially fuse the one or more components withinthe header core 2220.

In further examples, the header core 2220 can include various otherfeatures. For example, the header core 2220 can include one or more feet2236 to define a standoff between the header core 2220 and the devicecontainer 2202. The one or more feet 2236 can allow the header core 2220to be positioned parallel to a portion of the device container 2202. Inaddition, the one or more feet 2236 can be placed against or inengagement with a corresponding one or more anchor posts 2204 of thedevice container 2202. In further examples, the header core 2220 caninclude an antenna attachment feature 2226 similar to those describedherein for locating, supporting, and/or attaching an antenna 2208 withrespect to the header core 2220. In still further examples, the headercore 2220 can include a tag holder for an identification tag similar tothose described herein. In still further examples, the header core 2220can include one or more locating features for locating and/or routing ofone or more wires of the IMD 2200.

The header core 2220 can include one or more material relief features atlocations (e.g., at corners) to allow substantially free flow of moldmaterial and escape of air during overmolding of the header shell 2240,thereby allowing for a reduced number of mold defects and a reducedlikelihood of delamination occurring between the header core 2220 andthe header shell 2240. In some examples, a relief pattern can include aridge or other protrusion that acts to provide a break in the continuityof a surface and therefore, provide a barrier against continueddelamination. As such, in some examples, the header core 2220 caninclude a ridge, protrusion, or other relief pattern at or nearlocations in the header core 2220 which have an increased likelihood ofbeing a nucleation site of delamination, such as around a cavity 2234,in particular at a corner of the cavity 2234.

Referring to FIGS. 23 and 24, a modular header core 2320 is shown. Theheader core 2320, in various examples, can be used in a header of an IMDsimilar to those described herein. That is, the header core 2320 can beused to attach and locate components of the IMD prior to molding of aheader shell around the header core 2320 and also attach the header to adevice container of the IMD. In some examples, the header core 2320 canbe used in place of the header cores described herein.

In some examples, the modular header core 2320 includes core modules2320A, 2320B, 2320C that can be selectively coupled together to form theheader core 2320. In other examples, the header core 2320 can includemore or less than three core modules, depending on the type of IMD inwhich the header core 2320 is to be used and the application of the IMD.In various examples, the core modules 2320A, 2320B, 2320C can bedetachably engaged with one another to form the header core 2320. Forinstance, the core module 2320A can include one or more engagementfeatures 2323A configured to selectively couple to one or morecomplementary engagement features 2321B of the core module 2320B toengage the core modules 2320A, 2320B together. In some examples, theengagement features 2323A, 2321B include a peg and a corresponding hole.In some examples, the engagement features 2323A, 2321B engage with afriction fit in order to help maintain engagement of the core modules2320A, 2320B. In some examples, the engagement feature 2323A includes asubstantially rectangular slot and the engagement feature 2321B includesa segmented ring sized and shaped to frictionally fit within theengagement feature 2323A, wherein portions of the segmented ring can beconfigured to resiliently flex with frictional engagement within theengagement feature 2323A.

In further examples, the module core 2320C includes one or moreengagement features 2321C configured to selectively couple to one ormore complementary engagement features 2323B of the core module 2320B toengage the core modules 2320B, 2320C together. The engagement features2323B, 2321C can be similar to the engagement features 2323A, 2321Bdescribed herein.

In still further examples, the engagement features 2323A, 2321C cancorrespond to allow selective engagement of the core modules 2320A,2320C.

In some examples, at least one of the core modules 2320A, 2320B, 2320Cincludes a bore hole portion 2332. In further examples, at least one ofthe core modules 2320A, 2320B, 2320C includes more than one bore holeportion 2332. The one or more bore holes portions 2332, in someexamples, can be used to couple to components, such as leads. In someexamples, at least one of the core modules 2320A, 2320B, 2320C includesone or more cavities 2334 configured to accept one or more correspondingbore components, such bore components including, but not being limitedto, a connector block, a seal ring, a tip connector, or the like. Invarious examples, the cavity 2334 can be formed through a side of thecore module 2320A, 2320B, 2320C of the header core 2320 and intersectthe bore hole portion 2332, so that a bore component can be insertedinto the cavity 2334 from the side of the header core 2320 and be placedin position within the bore hole portion 2332. Alternatively, some borecomponents can be placed through the bore hole portion 2332 and locatedin position within the core module 2320A, 2320B, 2320C of the headercore 2320. The bore components, for instance, electrical contacts andthe like, can be configured to make electrical contact with a portion ofthe component (e.g., a terminal of the lead) inserted within the borehole, in order to electrically couple the lead or other component withat least one electronic module within the device container of the IMD.

The one or more bore hole portions 2332 can be inspected to confirmproper geometry, location with respect to other bore hole portions 2332,and/or location within the head core 2320. Once some or all of thecomponents are located within the header core 2320, the components ofthe header core 2320 can be tested to ensure proper placement within thebore hole portions 2332 and/or proper conductive functioning. By formingthe bore hole portions 2332 prior to connection of the header with thedevice container, the header core 2320 and the bore hole portions 2332can be tested and/or inspected prior to attachment of the header core2320 to the device container, as described herein. In the presentexamples of the modular header core 2320, not only can the header core2320 as a whole be tested and inspected, but each of the core modules2320A, 2320B, 2320C can be tested and/or inspected. If one of the coremodules 2320A, 2320B, 2320C is found to be defective in some manner,then the defective core module 2320A, 2320B, 2320C can be fixed orreplaced, further limiting losses.

In further examples, various combinations of core modules can be used toform various header cores for use within various types of IMDs. That is,a number of different header cores can be constructed using a relativelysmall variety of core modules. In various examples, the core modules canbe configured to each be capable of engaging with one another, such thatdifferent combinations of core modules can be engaged together to formdifferent models of header cores. In this way, stocks of different coremodules can be kept, rather than stocks of the different models ofheader cores, and the various core modules can be engaged in differentcombinations to form the various models of header cores needed for thevarious types of IMDs. This allows for header cores to be built-to-needand decreases the need for stockpiles of certain header cores.

Moreover, in some examples, the modular header core 2320 can allow formolds and molding methods of decreased complexity. By separating theheader core 2320 into core modules 2320A, 2320B, 2320C, each individualmold for the core modules 2320A, 2320B, 2320C includes a portion of theoverall number of cavities 2334 and bore hole portions 2332 of theheader core 2320, thereby making for less complex molds for each of theindividual core modules 2320A, 2320B, 2320C than a mold configured toform the entire header core with all of the bore hole portions andcavities. Additionally, by molding the core modules 2320A, 2320B, 2320Cseparately, substantially uniform wall thickness can be achieved in atleast a portion of the core modules 2320A, 2320B, 2320C. That is, blocksor otherwise thick portions of mold material (for instance, between borehole portions) can be limited in the core modules 2320A, 2320B, 2320C,thereby decreasing an amount of mold material needed for forming theheader core 2320. Also, because thicker portions of mold material oftentimes are more likely to be the site of voids, sinks, or other moldingdefects, limiting such thicker portions of the core modules 2320A,2320B, 2320C can decrease mold defects.

Referring to FIGS. 25-27, in some examples, a modular header core 2520is shown. The header core 2520, in various examples, can be used in aheader of an IMD similar to those described herein. That is, the headercore 2520 can be used to attach and locate components of the IMD priorto molding of a header shell around the header core 2520 and attachmentof the header to a device container of the IMD. In some examples, theheader core 2520 can be used in place of the header cores describedabove and used in similar manners to those described above.

In some examples, the modular header core 2520 includes core modules2520A, 2520B that can be selectively coupled together to form the headercore 2520. In the example shown in the referenced figures, the headercore 2520 includes two core modules 2520A, 2520B. In other examples, theheader core 2520 can include more or less than two core modules,depending on the type of IMD in which the header core 2520 is to be usedand the application of the IMD. In various examples, the core modules2520A, 2520B can be detachably engaged with one another to form theheader core 2520. For instance, the core module 2520A can include one ormore engagement features 2523A configured to selectively couple to oneor more complementary engagement features 2521B of the core module 2520Bto engage the core modules 2520A, 2520B together. In some examples, theengagement features 2523A, 2521B provide sliding engagement between thecore modules 2520A, 2520B. In some examples, the engagement features2523A, 2521B include interlocking hooks configured to slidingly engagethe core module 2520A with the core module 2520B. In some examples, theengagement features 2523A, 2521B engage with a friction fit in order tohelp maintain engagement of the core modules 2520A, 2520B.

In some examples, at least one of the core modules 2520A, 2520B includesa bore hole portion 2532. In further examples, at least one of the coremodules 2520A, 2520B includes more than one bore hole portion 2532. Theone or more bore holes portions 2532, in some examples, can be used tocouple to components, such as leads. In some examples, at least one ofthe core modules 2520A, 2520B includes one or more cavities 2534configured to accept one or more corresponding bore components, suchbore components including, but not being limited to, a connector block,a seal ring, a tip connector, or the like. In various examples, thecavity 2534 can be formed through a side of the core module 2520A, 2520Bof the header core 2520 and intersect the bore hole portion 2532, sothat a bore component can be inserted into the cavity 2534 from the sideof the header core 2520 and be placed in position within the bore holeportion 2532. Alternatively, some bore components can be placed throughthe bore hole portion 2532 and located in position within the coremodule 2520A, 2520B of the header core 2520. The bore components, forinstance, electrical contacts and the like, can be configured to makeelectrical contact with a portion of the component (i.e., a terminal ofthe lead) inserted within the bore hole, in order to electrically couplethe lead or other component with at least one electronic module withinthe device container of the IMD.

The one or more bore hole portions 2532 can be inspected to confirmproper geometry, location with respect to other bore hole portions 2532,and/or location within the head core 2520. Once some or all of thecomponents are located within the header core 2520, the components ofthe header core 2520 can be tested to ensure proper placement within thebore hole portions 2532 and/or proper conductive functioning. By formingthe bore hole portions 2532 prior to connection of the header with thedevice container, the header core 2520 and the bore hole portions 2532can be tested and/or inspected prior to attachment of the header core2520 to the device container. In the present examples of the modularheader core 2520, not only can the header core 2520, as a whole betested and inspected, but each of the core modules 2520A, 2520B can betested and/or inspected. If one of the core modules 2520A, 2520B, isfound to be defective in some manner, then only the defective coremodule 2520A, 2520B need be fixed or replaced.

As described herein with respect to FIGS. 23 and 24, variouscombinations of core modules can be used to form various header coresfor use within various types of IMDs. In various examples, the coremodules can be configured to each be capable of engaging with oneanother, such that different combinations of core modules can be engagedtogether to form different models of header cores. In this way, stocksof different core modules can be kept, rather than stocks of thedifferent models of header cores, and the various core modules can beengaged in different combinations to form the various models of headercores needed for the various types of IMDs. In some examples, the coremodules are configured to be engaged in any of a plurality ofconfigurations. That is, the core modules can be stackable or otherwiseengageable in various orders, sequences, or combinations to form aplurality of different header cores with the core modules. In otherexamples, the core modules are configured to be engaged in a particularconfiguration. That is, the core modules can be stackable or otherwiseengageable in a particular order, sequence, or combination to form aparticular header core with a combination of core modules.

Referring now to FIGS. 23-27, in some examples, a method of making anIMD including a modular header core 2320, 2520 is contemplated. In someexamples, a plurality of core modules 2320A, 2320B, 2320C, 2520A, 2520Bis selected for an IMD. In some examples, the plurality of core modulesincludes at least a first core module 2320A, 2520A and a second coremodule 2320B, 2520B. In further examples, the plurality of core modulesincludes at least a third core module 2520C. In further examples, themodular header core 2320, 2520 is formed by engaging the plurality ofcore modules 2320A, 2320B, 2320C, 2520A, 2520B with one another, asdescribed herein. In another example, the modular header core 2320, 2520is formed by slidingly engaging the plurality of core modules 2520A,2520B with one another. In some examples, a header shell is formedaround the modular header core 2320, 2520. In some examples, the headershell is molded around the modular header core 2320, 2520 in a mannersimilar to those described herein.

Referring to FIGS. 38 and 39, in some examples, an IMD 3800 includes aheader 3810 including a header core 3820 and a header shell 3840disposed around the header core 3820. In various examples, the header3810 includes one or more bore holes 3812. In some examples, asdescribed above, the header core 3820 can be formed first and thenattached to the device container 3802 by molding the header shell 3840around the header core 3820 and to the device container 3802. Althoughshown in the presently-referenced figures as a modular header core 3820,it should be understood that, in various examples, the header core 3820can include a modular header core, a partially modular header core, or aone-piece header core.

In some examples, the header 3810 includes a seal plug 3839 moldedwithin the overmolded header shell 3840. The seal plug 3839, in someexamples, is disposed within a seal plug receiver 3838 of the headercore 3820. In some examples, the seal plug receiver 3838 includes a wallextending from a surface of the header core 3820. In various examples,the seal plug 3839 is configured to seal an area around a set screw 3815(or other component of the IMD 3800). In some examples, the seal plug3839 is configured to allow access to the set screw 3815 for adjustment(tightening or loosening) of the set screw 3815 with a torque wrench orother tool configured to adjust the set screw 3815. In some examples,the set screw 3815 can be tightened to help retain a lead within thebore hole 3812, for instance, by bearing upon a surface of the lead (orlead pin). In some examples, the seal plug 3839 includes a resilientseal portion 3839A configured to provide a compression fit within theseal plug receiver 3838 to seal around the set screw 3815. The seal plug3839, in further examples, includes an exposed surface 3839B configuredto be exposed after overmolding. The exposed surface 3839B, in someexamples, can include a dimple or other feature configured to indicate alocation of an aperture or other opening 3839C within the seal plug3839. In various examples, the opening 3839C is configured to allow thetorque wrench or other tool to be sealably inserted through the sealplug 3839 for engagement with the set screw 3815 therein to allow foradjustment of the set screw 3815. When the tool is removed, the opening3839C is configured to sealably close (for instance, due to theresilient characteristics of the seal plug 3839). In this way, invarious examples, the seal plug allows for sealing of the area of theset screw 3815 while still allowing access to the set screw 3815 foradjustment of the set screw 3815.

In some examples, the seal plug 3839 can be disposed in the seal plugreceiver 3838 prior to overmolding of the header shell 3840 around theheader core 3820. That is, the seal plug 3839 is compressibly disposedand retained within the seal plug receiver 3838 and then the headershell 3840 is overmolded around the header core 3820. The overmolding ofthe header shell 3840, in some examples, bears upon a portion of theseal plug 3839 to retain the seal plug 3839 in place within the sealplug receiver 3838. In further examples, the exposed surface 3839B ofthe seal plug 3839 remains exposed after overmolding to allow accesswith the tool, as described herein.

By providing the seal plug receiver 3838 and allowing overmolding of theheader shell 3840 around the header core 3820 with the seal plug 3839 inplace, the seal plug 3839 seals the area of the set screw 3815 or othercomponent of the IMD 3800 and can eliminate steps involved with otherways of providing seal plugs in IMDs. For instance, the compressive sealcreated by the seal plug 3839 and the overmolding of the header shell3840 allow for sealing and retention of the seal plug 3839 with respectto the header 3810 of the IMD 3800 without the need to use a separatesealant or structure machined or molded into the header configured tomaintain the seal plug in place within the header. Additionally, theseal plug 3839 of the present examples allows for the overmolding of theheader shell 3840 without the need for a mold structure to form a sealplug opening in the header configured to ultimately receive the sealplug after molding. In this way, by overmolding the header shell 3840with the seal plug 3839 in place within the header core 3820, aftercompletion of the overmolding and curing of the header shell 3840, theIMD 3800 can substantially be ready for use in that the IMD 3800 neednot undergo further assembly steps to attach one or more seal plugs.Also, the configuration of the seal plug 3839 of the present examplesallows for sealing of the seal plug 3839 within the seal plug receiver3838 without the need for additional materials, such as a sealant oranother material. That said, in other examples, it is contemplated thata sealant or other material can be used with the present seal plug 3839in order to enhance the seal formed by the resilient seal portion 3839Aof the seal plug 3839.

Referring now to FIGS. 28 and 29, in some examples, an IMD 2800 includesa device container 2802 including at least one electronic module withinthe device container 2802. In some examples, the IMD 2802 includes aheader 2820 coupled to the device container 2802. In various examples,the header 2810 includes a header core 2820 and a header shell 2840disposed around the header core 2820. In some examples, the header shell2840 is attached to the device container 2802. In further examples, theheader shell 2840 can be molded around the header core 2820 and moldedto the device container 2802 in a similar manner to that describedherein with respect to other examples. In still further examples, theheader shell 2840 can be molded around the header core 2820 and attachedto the device container 2802 using adhesive, welding, or the like. Insome examples, the device container 2802 can include a textured surfacefor attachment of the header shell 2840 to the device container 2802, asdescribed herein.

In further examples, the header 2810 includes an antenna 2808 coupled tothe header 2810 and electrically coupled to the at least one electronicmodule within the device container 2802. In some examples, the antenna2808 is coupled to the header core 2820 and molded within the headershell 2840. In further examples, the antenna 2808 is supported by anantenna attachment feature 2826 of the header core 2820, which, forinstance, can be similar to one or more of the examples of antennaattachment features described herein. In an example, the antenna 2808 iselectrically coupled to the at least one electronic module with a wire2806.

In some examples, the header 2810 includes a first portion proximate theantenna 2808 and a second portion. In some examples, the first portionincludes a first dielectric constant that is lower than a seconddielectric constant of a second portion of the header 2810. Such aconfiguration can be beneficial to limit or otherwise decreasecapacitive losses between the antenna 2808 and one or more othermetallic or otherwise conductive components of the IMD 2800, such as,for instance, the device container 2802. In an example, the firstportion of the header 2810 can be disposed at least substantiallybetween the antenna 2808 and the device container 2802. Becausecapacitance is directly proportional to the dielectric constant, bycontrolling the first dielectric constant of the first portion betweenthe antenna 2808 and the device container 2802, the capacitance betweenthe antenna 2808 and the device container 2802 can be controlled,thereby controlling capacitive loss and, therefore, signal loss of theantenna 2808. In further examples, the first portion with the lowerdielectric constant can be disposed substantially between the antenna2808 and other conductive components of the IMD 2800, such as, forinstance, the one or more electrical contacts 2814, to limit capacitivelosses between the antenna 2808 and other conductive components.

In some examples, the first portion of the header 2810 includes theantenna attachment feature 2826. In some examples, the antennaattachment feature 2826 is engaged with the header core 2820. In otherexamples, the antenna attachment feature 2826 is integrally formed withthe header core 2820. The first portion of the header 2810, in someexamples, includes the header core 2820, and the second portion of theheader 2810 includes the header shell 2840, such that the header core2820 is formed from a material that includes a lower dielectric constantthan that of a material from which the header shell 2840 is formed.

In other examples, the first portion of the header 2810 includes a firstportion 2820A of the header core 2820 and the second portion of theheader 2810 includes a second portion 2820B of the header core 2820,wherein the first portion 2820A includes a lower dielectric constantthan that of the second portion 2820B. In this example, the header core2820 can include the first portion 2820A and the second portion 2820B.In further examples, the first portion 2820A of the header core 2820 caninclude the antenna attachment feature 2826. In a further example, thefirst portion 2820A and the second portion 2820B can be molded together.That is, the header core 2820 can be formed in a two-stage moldingoperation, with one of the first portion 2820A or the second portion2820B being formed with a first molding operation and the other of thefirst portion 2820A or the second portion 2820B being formed with asecond molding operation. In further examples, the second moldingoperation engages the first portion 2820A with the second portion 2820B.In another example, the first portion 2820A is mechanically attached tothe second portion 2820B. For instance, the first and second portions2820A, 2820B can include complementary engaging features to allowengagement of at least the first and second portions 2820A, 2820B toform the header core 2820. In some examples, the first and secondportions 2820A, 2820B of the header core 2820 can be similar to the coremodules of the modular header core examples described above. In otherexamples, the first and second portions 2820A, 2820B can be attachedusing a fastening substance, such as, for instance, a medical adhesiveor the like.

In various examples, the dielectric properties of the first portion ofthe header 2810 can be achieved in different ways. For instance, in anexample, the first portion can be formed from a specialized materialchosen for its particular dielectric properties. For instance, amaterial can be chosen for the first portion that includes a dielectricconstant that is less than that of the material from which the secondportion of the header 2810 is formed.

In other examples, the first portion can be formed from an aeratedmaterial. That is, in various examples, air or another gas can bebubbled through a material, for instance, during molding of the firstportion of the header 2810 to create air or other gas bubbles in thefirst portion of the header 2810 and make an aerated material or anaerated foam. Because air has a relatively low dielectric constant(slightly greater than one), the dielectric of the aerated material is afunction of the dielectric constants of the material and of air. Becauseair has a lower dielectric constant than the material being aerated, theinclusion of air bubbles within the material lowers the overalldielectric constant of the aerated material. The proportion of thematerial to air determines the overall dielectric constant of theaerated material. The higher the proportion of air in the aeratedmaterial, the lower the overall dielectric constant is as compared tothe dielectric constant of the unaerated material. Other gases, ormixtures of gases, can be used in other examples in much the samemanner, provided the gases are capable of being implanted within thebody and provided the gases do not react adversely when put in contactwith the material to be aerated or other materials of the IMD 2800.

In other examples, the first portion can be formed by mixing a lowdielectric constant material with mold material. In these examples, thelow dielectric constant material need only have a dielectric constantthat is lower than that of the mold material, such that the mixture ofthe low dielectric constant material and the mold material includes alower overall dielectric constant than does the mold material alone. Insome examples, a low dielectric constant solid material can be mixedwith the mold material to form a solid emulsion, which ultimately formsa solid filled material with curing of the mold material. In someexamples, the low dielectric constant material includes expandedpolytetrafluoroethylene (ePTFE). In still other examples, the lowdielectric constant material includes aerated or porous glass. In otherexamples, the low dielectric constant material can include a liquid.

By placing the lower dielectric constant material in a position withinthe IMD 2800 substantially between the antenna 2808 and the devicecontainer 2802 and/or other conductive components within or proximatethe IMD 2800, the capacitive loss between the antenna 2808 and thedevice container 2802 and/or other conductive components within orproximate the IMD 2800 can be decreased from the capacitive loss thatwould have occurred if a material without a lower dielectric constant.Other conductive components can include the electrical contacts 2814(including a connector block, a seal ring, a tip connector, or thelike), the wires 2806, or the like. By doing so, signal losses from theantenna 2808 can be decreased. Decreased signal losses can lead to abetter transmission range for the antenna 2808 and/or lower poweroperation of the antenna 2808, among other things.

In examples of the header 2810 including a low dielectric portion inwhich the low dielectric portion is formed by aerating the material fromwhich the low dielectric portion is formed, in some examples, thereexists the possibility that the one or more bubbles, voids, pockets, orother spaces in the material could start filling with fluid afterimplantation within the body due to saturation of the material and/ormaterials of the header 2810 over time. In various examples, the lowdielectric portion of the header 2810 can include a moisture shield,coating, or the like to decrease the likelihood that moisture willaccumulate within the one or more bubbles, voids, pockets, or otherspaces within the low dielectric portion of the header 2810. One reasonfor inhibiting the accumulation of moisture within the one or morebubbles, voids, pockets, or other spaces is because body fluid has arelatively high dielectric constant, thereby increasing the overalldielectric constant of the portion of the header 2810, potentiallyleading to higher capacitive losses between the antenna 2808 and thedevice container 2802 and increased signal loss. In some examples, themoisture shield or coating can be formed by at least partially coatingthe low dielectric portion of the header 2810 with a moisture barrier,such as a polymeric material. In some examples, Parylene can be used toform the moisture barrier.

In some examples, the header core 2820 is formed by molding. In furtherexamples, the header core 2820 is positioned with respect to the devicecontainer 2802, any connections are made between the header core 2820and the device container 2802, and the header shell 2840 is then moldedaround the header shell 2820 and attached to the device container 2802.Examples of such overmolding of the header shell are described herein,and the overmolding of the header shell 2840 of the present examples canbe similar to such described examples. However, in some examples,molding of the low dielectric portion of the header 2810 using anaerated material can lead to bubbles, voids, or the like forming at asurface of the molded portion. Such surface voids can lead to moldinconsistencies, defects, or the like. As such, in some examples, theminimization of such surface voids can be desirable. In some examples,surface voids in the low dielectric portion can be decreased by firstfilling a mold for the low dielectric portion with an unaeratedmaterial, then draining the material from the mold. By doing so,interior surfaces of the mold are wetted to form a coating over theinterior surfaces of the mold. The mold can then be filled with theaerated material to form the low dielectric portion. Because theinterior surfaces of the mold were coated with the unaerated materialprior to filling the mold with the aerated material, the likelihood ofsurface voids being formed in the low dielectric portion can bedecreased.

Referring to FIGS. 30 and 31, in some examples, a header core 3020 of anIMD includes a first portion 3020A including a material including arelatively low dielectric constant and a second portion 3020B attachedto the first portion 3020A. Various aspects of the example shown inFIGS. 30 and 31 can be similar to those described herein with respect tothe header 2810, including the materials used to form the header 2810and the methods of forming the header 2810. As such, at least portionsof the description are applicable to the presently-referenced headercore 3020. In some examples, the header core 3020 includes an antennaattachment feature 3026 configured to support, locate, or otherwiseposition an antenna 3008 with respect to the header core 3020 and,ultimately, with respect to a device container of an IMD to which theheader core 3020 is attached. In some examples, the antenna attachmentfeature 3026 includes a channel configured to capture the antenna 3008along at least a portion of the antenna 3008. In some examples, thefirst portion 3020A of the header core 3020 can be formed from amaterial having a relatively low dielectric constant. In some examples,the first portion 3020A is disposed substantially between the antenna3008 and conductive components of the IMD, such as one or moreelectrical contacts 3014 of one or more bore hole portions 3032 theheader core 3020 (including a connector block, a seal ring, a tipconnector, or the like), wires of the IMD, a device container of theIMD, or the like. Due to the geometry of the antenna 3008, in someexamples, the first portion 3020 extends along a side of the header core3020 and around a front of the header core 3020. The first portion3020A, in an example, includes a leg 3020C that extends along one sideof the header core 3020 to accommodate the geometry of the antenna 3008.In some examples, the leg 3020C is integrally formed with the firstportion 3020A. In other examples, the leg 3020C can be a separate piecefrom the rest of the first portion 3020A that is separately attached tothe header core 3020.

In some examples, the first portion 3020A is mechanically attached tothe second portion 3020B, for instance, using complementary engagingfeatures. In some examples, the first portion 3020A is mechanicallyattached to the second portion 3020B, for instance, using an adhesiveeither alone or in addition to complementary engaging features. Inexamples in which the leg 3020C is separately formed from the rest ofthe first portion 3020A, the leg 3020C can include an adhesive stripthat can be mounted to an outer surface of the second portion 3020B at aselected position to accommodate the antenna 3008. In further examples,the outer surface of the second portion 3020B can include a channel 3021within which the leg 3020C can be disposed. In such examples, the leg3020C, whether separate from or integral with the rest of the firstportion 3020A, can be retained within the channel 3021 using mechanicalcomplementary engaging features, a friction fit, and/or adhesive. Insome examples, the first and second portions 3020A, 3020B (and the leg3020C, if separately formed from the first portion 3020A) are engaged toone another in manners similar to those described herein with respect tothe modular header core examples.

Additional Notes and Examples

Example 1 can include subject matter (such as an apparatus, a method, ameans for performing acts) that can include or can use an implantabledevice. The implantable device can include a metallic device container.The implantable device can include a textured surface on a portion ofthe metallic device container, having an area root mean square valuebetween 3.05 μm and 10.2 μm. The implantable device can include athermoset polymer header forming an interface with at least a portion ofthe textured surface.

Example 2 can include or use, or can optionally be combined with thesubject matter of Example 1 to include or use an implantable device,wherein the textured surface includes a laser treated surface includinga number of substantially spherical particles.

Example 3 can include or use, or can optionally be combined with thesubject matter of Examples 1-2 to include or use an implantable device,wherein the thermoset polymer is an epoxy.

Example 4 can include or use, or can optionally be combined with thesubject matter of Examples 1-3 to include or use an implantable device,wherein the epoxy header is cast in place.

Example 5 can include or use, or can optionally be combined with thesubject matter of Examples 1-4 to include or use an implantable device,wherein the epoxy header is injection molded in place.

Example 6 can include or use, or can optionally be combined with thesubject matter of Examples 1-5 to include or use an implantable device,wherein the textured surface has an area root mean square value between3.81 μm and 8.89 μm.

Example 7 can include or use, or can optionally be combined with thesubject matter of Examples 1-6 to include or use an implantable device,wherein the textured surface has an area root mean square value between3.30 μm and 3.81 μm.

Example 8 can include or use, or can optionally be combined with thesubject matter of Examples 1-7 to include or use an implantable device,wherein the epoxy header has a Shore D hardness between approximately 80and 90.

Example 9 can include or use, or can optionally be combined with thesubject matter of Examples 1-8 to include or use an implantable device,wherein a volume fraction of resin to hardener in the epoxy isapproximately 2 to 1.

Example 10 can include or use, or can optionally be combined with thesubject matter of Examples 1-9 to include or use an implantable device,wherein the laser treated surface includes a periodic pattern.

Example 11 can include or use, or can optionally be combined with thesubject matter of Examples 1-10 to include or use an implantable device,wherein the laser treated surface includes at least one pattern ofridges and troughs.

Example 12 can include or use, or can optionally be combined with thesubject matter of Examples 1-11 to include or use an implantable device,wherein the epoxy header is substantially transparent.

Example 13 can include or use, or can optionally be combined with thesubject matter of Examples 1-12 to include or use an implantable device,wherein the epoxy header has a glass transition of approximately 70degrees C.

Example 14 can include or use, or can optionally be combined with thesubject matter of Examples 1-13 to include or use an implantable device,wherein, in side load testing, the thermoset polymer header fails in thebulk for a metallic device container thickness between 16 mm and 4 mm.

Example 15 can include or use, or can optionally be combined with thesubject matter of Examples 1-14 to include or use an implantable device,wherein, in side load testing, the thermoset polymer header fails in thebulk for a metallic device container thickness between 14 mm and 6 mm.

Example 16 can include or use, or can optionally be combined with thesubject matter of Examples 1-15 to include or use an implantable device,wherein, in side load testing, the thermoset polymer header fails in thebulk for a metallic device container thickness between 12 mm and 8 mm.

Example 17 can include or use, or can optionally be combined with thesubject matter of Examples 1-16 to include or use a method. The methodcan include texturing an interface surface of an implantable devicecontainer. The method can also include raising a temperature of an epoxyresin to lower its viscosity. The method can also include injecting amixture of the epoxy resin and a hardener in a contained space tocontact the interface surface of the implantable device container. Themethod can also include driving the mixture to a first temperature for afirst amount of time. The method can also include driving the mixture toa second temperature to at least partially cure the mixture.

Example 18 can include or use, or can optionally be combined with thesubject matter of Examples 1-17 to include or use a method, whereinraising the temperature of an epoxy resin to lower its viscosityincludes raising a temperature to approximately 50° C.

Example 19 can include or use, or can optionally be combined with thesubject matter of Examples 1-18 to include or use a method, whereininjecting the mixture includes injecting at a pressure of less than0.034 MPa.

Example 20 can include or use, or can optionally be combined with thesubject matter of Examples 1-19 to include or use a method, whereininjecting the mixture further includes injecting into a mold that ispre-heated to approximately 50° C.

Example 21 can include or use, or can optionally be combined with thesubject matter of Examples 1-20 to include or use a method, whereindriving the mixture to a first temperature includes driving the mixtureto between approximately 25° C. and 55° C. for a duration ofapproximately 40 minutes.

Example 22 can include or use, or can optionally be combined with thesubject matter of Examples 1-21 to include or use a method, whereindriving the mixture to a second temperature includes driving the mixtureto a temperature of approximately 85° C. for approximately 10 minutes.

Example 23 can include or use, or can optionally be combined with thesubject matter of Examples 1-22 to include or use a method, whereintexturing the interface surface includes particle blasting.

Example 24 can include or use, or can optionally be combined with thesubject matter of Examples 1-23 to include or use a method, whereintexturing the interface surface includes laser treating.

Example 25 can include or use, or can optionally be combined with thesubject matter of Examples 1-24 to include or use a method, whereinlaser treating the interface surface includes laser treating a texturedsurface having an area root mean square value between 3.05 μm and 10.2μm.

Example 26 can include or use, or can optionally be combined with thesubject matter of Examples 1-25 to include or use a method, whereinlaser treating the interface surface includes laser treating a texturedsurface having an area root mean square value between 3.81 μm and 8.89μm.

Example 27 can include or use, or can optionally be combined with thesubject matter of Examples 1-26 to include or use a method, whereinlaser treating the interface surface includes laser treating a texturedsurface having an area root mean square value between 3.30 μm and 3.81μm.

Example 28 can include, or can be combined with the subject matter ofone or any combination of Examples 1-27 to optionally include, subjectmatter (such as an apparatus, such as an implantable medical device, amethod, a means for performing acts, or a machine-readable mediumincluding instructions that, when performed by the machine, cause themachine to perform acts) that can comprise: a device container includingan electronic module within the device container; a header coreincluding an electronic connection feature electrically coupled to theelectronic module within the device container, the electronic connectionfeature configured to engage with a lead, the header core including atag holder; an identification tag engaged with the tag holder, the tagholder configured to locate the identification tag in a selectedposition with respect to the header core; and a molded header shelldisposed around the header core and attached to the device container.

Example 29 can include or use, or can optionally be combined with thesubject matter of Examples 1-28 to include or use an implantable medicaldevice, wherein the identification tag is configured to be x-rayreadable.

Example 30 can include or use, or can optionally be combined with thesubject matter of Examples 1-29 to include or use an implantable medicaldevice, wherein the identification tag includes tungsten.

Example 31 can include or use, or can optionally be combined with thesubject matter of Examples 1-30 to include or use an implantable medicaldevice, wherein the tag holder includes a slot in the header coreconfigured to engage with a portion of the identification tag.

Example 32 can include or use, or can optionally be combined with thesubject matter of Examples 1-31 to include or use an implantable medicaldevice, wherein the tag holder includes: a first slot in the header coreconfigured to engage with a portion of the identification tag; and asecond slot in the header core substantially perpendicular to the firstslot.

Example 33 can include or use, or can optionally be combined with thesubject matter of Examples 1-32 to include or use an implantable medicaldevice, wherein the identification tag includes a post configured toengage with the tag holder of the header core.

Example 34 can include or use, or can optionally be combined with thesubject matter of Examples 1-33 to include or use an implantable medicaldevice, wherein the post of the identification tag includes an indexingfeature configured to position and maintain the identification tag in aselected orientation with respect to the header core.

Example 35 can include or use, or can optionally be combined with thesubject matter of Examples 1-34 to include or use an implantable medicaldevice, wherein the tag holder includes a surface of the header core,and the identification tag is printed on the surface of the header core.

Example 36 can include or use, or can optionally be combined with thesubject matter of Examples 1-35 to include or use an implantable medicaldevice, wherein the header core is formed from a first material and theheader shell is formed from a second material, the first material beingdifferent from the second material.

Example 37 can include or use, or can optionally be combined with thesubject matter of Examples 1-36 to include or use an implantable medicaldevice, wherein the header core is configured to inhibit mold defects inthe header shell.

Example 38 can include, or can be combined with the subject matter ofone or any combination of Examples 1-37 to optionally include, subjectmatter (such as an apparatus, such as an implantable medical device, amethod, a means for performing acts, or a machine-readable mediumincluding instructions that, when performed by the machine, cause themachine to perform acts) that can comprise: a device container includingan electronic module within the device container; a header coreincluding an antenna attachment feature; an antenna engaged with theantenna attachment feature and electrically coupled with the electronicmodule within the device container, the antenna attachment featureconfigured to locate the antenna in a selected position with respect tothe header core; and a molded header shell disposed around the headercore and attached to the device container, the header shell disposedaround and configured to retain the antenna in the selected position.

Example 39 can include or use, or can optionally be combined with thesubject matter of Examples 1-38 to include or use an implantable medicaldevice, wherein the antenna attachment feature includes ridges spaced toaccommodate the antenna between the ridges.

Example 40 can include or use, or can optionally be combined with thesubject matter of Examples 1-39 to include or use an implantable medicaldevice, wherein one or more of the ridges of the antenna attachmentfeature are disposed between portions of the antenna and are configuredto maintain spacing between the portions of the antenna.

Example 41 can include or use, or can optionally be combined with thesubject matter of Examples 1-40 to include or use an implantable medicaldevice, wherein the antenna attachment feature includes a retentionfeature configured to grip at least a portion of the antenna.

Example 42 can include or use, or can optionally be combined with thesubject matter of Examples 1-41 to include or use an implantable medicaldevice, wherein the retention feature is configured to frictionallyretain at least the portion of the antenna.

Example 43 can include or use, or can optionally be combined with thesubject matter of Examples 1-42 to include or use an implantable medicaldevice, wherein the antenna attachment feature is configured to maintaina substantially constant distance between the antenna and a patient.

Example 44 can include or use, or can optionally be combined with thesubject matter of Examples 1-43 to include or use an implantable medicaldevice, wherein the antenna attachment feature includes a removableportion configured to detachably engage with the header core.

Example 45 can include or use, or can optionally be combined with thesubject matter of Examples 1-44 to include or use an implantable medicaldevice, wherein the antenna attachment feature includes a channel.

Example 46 can include or use, or can optionally be combined with thesubject matter of Examples 1-45 to include or use an implantable medicaldevice, wherein the channel includes one or more portions configured tobe crimped to retain the antenna within the channel.

Example 47 can include or use, or can optionally be combined with thesubject matter of Examples 1-46 to include or use an implantable medicaldevice, wherein the antenna includes a printed antenna disposed on theantenna attachment feature of the header core.

Example 48 can include or use, or can optionally be combined with thesubject matter of Examples 1-47 to include or use an implantable medicaldevice, wherein the header core is formed from a first material and theheader shell is formed from a second material, the first material beingdifferent from the second material.

Example 49 can include or use, or can optionally be combined with thesubject matter of Examples 1-48 to include or use an implantable medicaldevice, wherein the header core is configured to inhibit mold defects inthe header shell.

Example 50 can include, or can be combined with the subject matter ofone or any combination of Examples 1-49 to optionally include, subjectmatter (such as an apparatus, such as an implantable medical device, amethod, a means for performing acts, or a machine-readable mediumincluding instructions that, when performed by the machine, cause themachine to perform acts) that can comprise: a device container includingan electronic module within the device container; a header coreincluding a bore hole portion and at least two electronic connectionfeatures disposed within the bore hole portion, the bore hole portionincluding at least one cavity configured to allow placement of at leastone of the electronic connection features within the bore hole portion,the at least two electronic connection features being electricallycoupled to the electronic module within the device container, the atleast two electronic connection features being configured to engage witha lead disposed within the bore hole portion, wherein the header core isconfigured to allow location of the at least two electronic connectionfeatures in a selected configuration within the bore hole portion; and aheader shell disposed around the header core and attached to the devicecontainer.

Example 51 can include or use, or can optionally be combined with thesubject matter of Examples 1-50 to include or use an implantable medicaldevice, wherein the header shell is molded around the header core.

Example 52 can include or use, or can optionally be combined with thesubject matter of Examples 1-51 to include or use an implantable medicaldevice, wherein at least one of the electronic connection features issealed within the cavity of the header core.

Example 53 can include or use, or can optionally be combined with thesubject matter of Examples 1-52 to include or use an implantable medicaldevice, comprising a wire electrically coupling the electronicconnection feature to the electronic module within the device container,wherein the header core includes a locating feature configured tomaintain the wire in a selected position with respect to the headercore.

Example 54 can include or use, or can optionally be combined with thesubject matter of Examples 1-53 to include or use an implantable medicaldevice, wherein the header core includes a standoff configured toposition the header core in a selected position with respect to thedevice container.

Example 55 can include or use, or can optionally be combined with thesubject matter of Examples 1-54 to include or use an implantable medicaldevice, wherein the header core includes a material relief configured toinhibit delamination of the header shell.

Example 56 can include or use, or can optionally be combined with thesubject matter of Examples 1-55 to include or use an implantable medicaldevice, wherein the header core and the header shell are formed from thesame material.

Example 57 can include or use, or can optionally be combined with thesubject matter of Examples 1-56 to include or use an implantable medicaldevice, wherein the header core is formed from a first material and theheader shell is formed from a second material.

Example 58 can include or use, or can optionally be combined with thesubject matter of Examples 1-57 to include or use an implantable medicaldevice, comprising a seal plug disposed within a receiver of the headercore and at least partially retained within the receiver by the headershell, the seal plug configured to sealingly allow access through theseal plug.

Example 59 can include or use, or can optionally be combined with thesubject matter of Examples 1-58 to include or use an implantable medicaldevice, wherein the seal plug is configured to sealingly allow access toa set screw of the header core.

Example 60 can include or use, or can optionally be combined with thesubject matter of Examples 1-59 to include or use an implantable medicaldevice, wherein the header shell is molded over a portion of the sealplug to at least partially retain the seal plug within the receiver ofthe header core.

Example 61 can include, or can be combined with the subject matter ofone or any combination of Examples 1-60 to optionally include, subjectmatter (such as an apparatus, such as an implantable medical device, amethod, a means for performing acts, or a machine-readable mediumincluding instructions that, when performed by the machine, cause themachine to perform acts) that can comprise: forming a header core, theheader core including a bore hole portion, the bore hole portionincluding at least one cavity configured to allow placement of anelectronic connection feature within the bore hole portion, theelectronic connection feature configured to engage with a lead disposedwithin the bore hole portion; inspecting the bore hole portion prior toattachment of the header core with a device container; attaching theheader core to the device container; and forming a header shell aroundthe header core and at least a portion of the device container.

Example 62 can include or use, or can optionally be combined with thesubject matter of Examples 1-61 to include or use a method, whereininspecting the header core includes verifying geometry and location ofthe bore hole portion.

Example 63 can include or use, or can optionally be combined with thesubject matter of Examples 1-62 to include or use a method, whereininspecting the header core includes electrically testing the electronicconnection feature within the bore hole portion.

Example 64 can include or use, or can optionally be combined with thesubject matter of Examples 1-63 to include or use a method, whereinforming the header core includes sealing the electronic connectionfeature within the cavity.

Example 65 can include or use, or can optionally be combined with thesubject matter of Examples 1-64 to include or use a method, whereinsealing the electronic connection feature within the cavity includesinduction heating the header core to seal the electronic connectionfeature within the cavity.

Example 66 can include or use, or can optionally be combined with thesubject matter of Examples 1-65 to include or use a method, whereinsealing the electronic connection feature within the cavity includeslaser heating the header core to seal the electronic connection featurewithin the cavity.

Example 67 can include or use, or can optionally be combined with thesubject matter of Examples 1-66 to include or use a method, whereinsealing the electronic connection feature within the cavity includesusing an adhesive to seal the electronic connection feature within thecavity.

Example 68 can include or use, or can optionally be combined with thesubject matter of Examples 1-67 to include or use a method, whereinforming the header shell includes molding the header shell around theheader core, wherein the electronic connection feature sealed within thecavity inhibits mold material from entering the cavity or the bore holeportion during molding of the header shell.

Example 69 can include or use, or can optionally be combined with thesubject matter of Examples 1-68 to include or use a method, whereinforming the header core includes forming a locating feature in theheader core, the locating feature configured to maintain a wire in aselected location with respect to the header core.

Example 70 can include or use, or can optionally be combined with thesubject matter of Examples 1-69 to include or use a method, comprisingbending one or more wires from the device container into one or moreselected positions configured for attachment to the header core, whereinattaching the header core to the device container includes attaching atleast one of the wires to the electronic connection feature.

Example 71 can include or use, or can optionally be combined with thesubject matter of Examples 1-70 to include or use a method, whereinbending the one or more wires includes using a template to bend the oneor more wires into the one or more selected positions configured forattachment to the header core.

Example 72 can include or use, or can optionally be combined with thesubject matter of Examples 1-71 to include or use a method, whereinbending the one or more wires includes using a bending tool to bend theone or more wires into the one or more selected positions configured forattachment to the header core.

Example 73 can include or use, or can optionally be combined with thesubject matter of Examples 1-72 to include or use a method, whereinforming the header shell includes molding the header shell around theheader core.

Example 74 can include or use, or can optionally be combined with thesubject matter of Examples 1-73 to include or use a method, whereinmolding includes using a mold apparatus configured to reduce flashingpresent on the header shell.

Example 75 can include or use, or can optionally be combined with thesubject matter of Examples 1-74 to include or use a method, whereinmolding includes using a mold apparatus configured to reduce flashingpresent on the header shell proximate to one or more bore holes.

Example 76 can include or use, or can optionally be combined with thesubject matter of Examples 1-75 to include or use a method, comprisingdisposing a seal plug within a receiver of the header core, the sealplug configured to sealingly allow access through the seal plug.

Example 77 can include or use, or can optionally be combined with thesubject matter of Examples 1-76 to include or use a method, whereinforming the header shell includes forming the header shell over aportion of the seal plug to at least partially retain the seal plugwithin the receiver of the header core.

Example 78 can include, or can be combined with the subject matter ofone or any combination of Examples 1-77 to optionally include, subjectmatter (such as an apparatus, such as an implantable medical device, amethod, a means for performing acts, or a machine-readable mediumincluding instructions that, when performed by the machine, cause themachine to perform acts) that can comprise: a device container includingan electronic module within the device container; a modular header coreincluding: a first core module including a first bore hole portion of afirst bore hole, the first bore hole portion configured to couple afirst electrical component with the electronic module; and a second coremodule including a second bore hole portion of a second bore holedifferent than the first bore hole, the second bore hole portionconfigured to couple a second electrical component with the electronicmodule, wherein the first core module is detachably engaged with thesecond core module; and a header shell disposed around the modularheader core and attached to the device container.

Example 79 can include or use, or can optionally be combined with thesubject matter of Examples 1-78 to include or use an implantable medicaldevice, wherein the first core module includes a first electronicconnection feature electrically coupled to the electronic module withinthe device container, the first electronic connection feature configuredto engage with the first electrical component.

Example 80 can include or use, or can optionally be combined with thesubject matter of Examples 1-79 to include or use an implantable medicaldevice, wherein the second core module includes a second electronicconnection feature electrically coupled to the electronic module withinthe device container, the second electronic connection featureconfigured to engage with the second electrical component.

Example 81 can include or use, or can optionally be combined with thesubject matter of Examples 1-80 to include or use an implantable medicaldevice, wherein the first core module is frictionally engaged with thesecond core module.

Example 82 can include or use, or can optionally be combined with thesubject matter of Examples 1-81 to include or use an implantable medicaldevice, wherein the first core module is slidingly coupled with thesecond core module.

Example 83 can include or use, or can optionally be combined with thesubject matter of Examples 1-82 to include or use an implantable medicaldevice, wherein the header shell and the modular header core are formedfrom a first material.

Example 84 can include or use, or can optionally be combined with thesubject matter of Examples 1-83 to include or use an implantable medicaldevice, wherein the header shell is formed from a first material and themodular header core is formed from a second material.

Example 85 can include or use, or can optionally be combined with thesubject matter of Examples 1-84 to include or use an implantable medicaldevice, wherein the header shell is molded around the modular headercore.

Example 86 can include, or can be combined with the subject matter ofone or any combination of Examples 1-85 to optionally include, subjectmatter (such as an apparatus, such as an implantable medical device, amethod, a means for performing acts, or a machine-readable mediumincluding instructions that, when performed by the machine, cause themachine to perform acts) that can comprise: selecting a plurality ofcore modules for an implantable medical device, the plurality of coremodules being selected according to the application of the implantablemedical device; forming a modular header core including engaging theplurality of core modules with one another; and forming a header shellaround the modular header core.

Example 87 can include or use, or can optionally be combined with thesubject matter of Examples 1-86 to include or use a method, whereinselecting the plurality of core modules includes selecting at least afirst core module and a second core module.

Example 88 can include or use, or can optionally be combined with thesubject matter of Examples 1-87 to include or use a method, whereinselecting at least the first core module and the second core moduleincludes selecting the first core module including a first bore holeportion of a first bore hole and selecting the second core moduleincluding a second bore hole portion of a second bore hole differentthan the first bore hole.

Example 89 can include or use, or can optionally be combined with thesubject matter of Examples 1-88 to include or use a method, whereinselecting the plurality of core modules includes selecting at least athird core module.

Example 90 can include or use, or can optionally be combined with thesubject matter of Examples 1-89 to include or use a method, whereinselecting at least the third core module includes selecting the thirdcore module including a third bore hole portion of a third bore holedifferent than at least one of the first bore hole and the second borehole.

Example 91 can include or use, or can optionally be combined with thesubject matter of Examples 1-90 to include or use a method, whereinforming the header shell around the modular header core includes moldingthe header shell around the modular header core.

Example 92 can include or use, or can optionally be combined with thesubject matter of Examples 1-91 to include or use a method, whereinforming the modular header core includes frictionally engaging theplurality of core modules with one another.

Example 93 can include or use, or can optionally be combined with thesubject matter of Examples 1-92 to include or use a method, whereinforming the modular header core includes slidingly engaging theplurality of core modules with one another.

Example 94 can include or use, or can optionally be combined with thesubject matter of Examples 1-93 to include or use a method, whereinforming the header shell includes forming the header shell from amaterial similar to a material of the modular header core.

Example 95 can include or use, or can optionally be combined with thesubject matter of Examples 1-94 to include or use a method, whereinforming the header shell includes forming the header shell from amaterial different than a material of the modular header core.

Example 96 can include or use, or can optionally be combined with thesubject matter of Examples 1-95 to include or use a method, wherein theplurality of core modules are configured to be engaged in a plurality ofdifferent configurations, wherein forming the modular header coreincludes selecting one of the plurality of different configurations andengaging the plurality of core modules in the one of the plurality ofdifferent configurations to form the modular header core.

Example 97 can include or use, or can optionally be combined with thesubject matter of Examples 1-96 to include or use a method, whereinforming the modular header core includes engaging the plurality of coremodules, wherein the plurality of core modules are configured to beengaged in a particular configuration to form the modular header core.

Example 98 can include, or can be combined with the subject matter ofone or any combination of Examples 1-97 to optionally include, subjectmatter (such as an apparatus, such as an implantable medical device, amethod, a means for performing acts, or a machine-readable mediumincluding instructions that, when performed by the machine, cause themachine to perform acts) that can comprise: a device container includingan electronic module within the device container; a header coupled tothe device container, the header including: a header core including aconductive member electrically coupled to the electronic module withinthe device container; and a header shell disposed around the header coreand attached to the device container; and an antenna coupled to theheader core and electrically coupled to the electronic module, wherein afirst portion of the header is proximate the antenna, the first portionincluding a first dielectric constant that is lower than a seconddielectric constant of a second portion of the header.

Example 99 can include or use, or can optionally be combined with thesubject matter of Examples 1-98 to include or use an implantable medicaldevice, wherein the first portion of the header is disposed between theantenna and the conductive member.

Example 100 can include or use, or can optionally be combined with thesubject matter of Examples 1-99 to include or use an implantable medicaldevice, wherein the first portion of the header is disposed between theantenna and the device container.

Example 101 can include or use, or can optionally be combined with thesubject matter of Examples 1-100 to include or use an implantablemedical device, wherein the first portion of the header includes anantenna attachment feature.

Example 102 can include or use, or can optionally be combined with thesubject matter of Examples 1-101 to include or use an implantablemedical device, wherein the antenna attachment feature is engaged withthe header core.

Example 103 can include or use, or can optionally be combined with thesubject matter of Examples 1-102 to include or use an implantablemedical device, wherein the antenna attachment feature is integrallyformed with the header core.

Example 104 can include or use, or can optionally be combined with thesubject matter of Examples 1-103 to include or use an implantablemedical device, wherein the first portion includes aerated foam.

Example 105 can include or use, or can optionally be combined with thesubject matter of Examples 1-104 to include or use an implantablemedical device, wherein the header core forms the first portion and theheader shell forms the second portion.

Example 106 can include or use, or can optionally be combined with thesubject matter of Examples 1-105 to include or use an implantablemedical device, wherein the header core includes the first portion andthe second portion.

Example 107 can include or use, or can optionally be combined with thesubject matter of Examples 1-106 to include or use an implantablemedical device, wherein the first and second portions are moldedtogether.

Example 108 can include or use, or can optionally be combined with thesubject matter of Examples 1-107 to include or use an implantablemedical device, wherein the first portion is mechanically attached tothe second portion.

Example 109 can include or use, or can optionally be combined with thesubject matter of Examples 1-108 to include or use an implantablemedical device, wherein the conductive member includes a wire.

Example 110 can include or use, or can optionally be combined with thesubject matter of Examples 1-109 to include or use an implantablemedical device, wherein the conductive member includes a connectorblock.

Example 111 can include or use, or can optionally be combined with thesubject matter of Examples 1-110 to include or use an implantablemedical device, wherein the header shell is molded around the headercore.

Example 112 can include or use, or can optionally be combined with thesubject matter of Examples 1-111 to include or use an implantablemedical device, wherein the first portion includes solid filledmaterial.

Example 113 can include or use, or can optionally be combined with thesubject matter of Examples 1-112 to include or use an implantablemedical device, wherein the solid filled material includes expandedpolytetrafluoroethylene.

Example 114 can include or use, or can optionally be combined with thesubject matter of Examples 1-113 to include or use an implantablemedical device, wherein the solid filled material includes porous glass.

These non-limiting examples can be combined in any permutation orcombination.

The above detailed description includes references to the accompanyingdrawings, which form a part of the detailed description. The drawingsshow, by way of illustration, specific embodiments in which theinvention can be practiced. These embodiments are also referred toherein as “examples.” Such examples can include elements in addition tothose shown or described. However, the present inventors alsocontemplate examples in which only those elements shown or described areprovided. Moreover, the present inventors also contemplate examplesusing any combination or permutation of those elements shown ordescribed (or one or more aspects thereof), either with respect to aparticular example (or one or more aspects thereof), or with respect toother examples (or one or more aspects thereof) shown or describedherein.

In the event of inconsistent usages between this document and anydocuments incorporated by reference, the usage in this documentcontrols.

In this document, the terms “a” or “an” are used, as is common in patentdocuments, to include one or more than one, independent of any otherinstances or usages of“at least one” or “one or more.” In this document,the term “or” is used to refer to a nonexclusive or, such that “A or B”includes “A but not B,” “B but not A,” and “A and B,” unless otherwiseindicated. In this document, the terms “including” and “in which” areused as the plain-English equivalents of the respective terms“comprising” and “wherein.” Also, in the following claims, the terms“including” and “comprising” are open-ended, that is, a system, device,article, or process that includes elements in addition to those listedafter such a term in a claim are still deemed to fall within the scopeof that claim. Moreover, in the following claims, the terms “first,”“second,” and “third,” etc. are used merely as labels, and are notintended to impose numerical requirements on their objects.

The above description is intended to be illustrative, and notrestrictive. For example, the above-described examples (or one or moreaspects thereof) may be used in combination with each other. Otherembodiments can be used, such as by one of ordinary skill in the artupon reviewing the above description. The Abstract is provided to complywith 37 C.F.R. §1.72(b), to allow the reader to quickly ascertain thenature of the technical disclosure. It is submitted with theunderstanding that it will not be used to interpret or limit the scopeor meaning of the claims. Also, in the above Detailed Description,various features may be grouped together to streamline the disclosure.This should not be interpreted as intending that an unclaimed disclosedfeature is essential to any claim. Rather, inventive subject matter maylie in less than all features of a particular disclosed embodiment.Thus, the following claims are hereby incorporated into the DetailedDescription, with each claim standing on its own as a separateembodiment, and it is contemplated that such embodiments can be combinedwith each other in various combinations or permutations. The scope ofthe invention should be determined with reference to the appendedclaims, along with the full scope of equivalents to which such claimsare entitled.

1-20. (canceled)
 21. An implantable medical device, comprising: a devicecontainer including an electronic module within the device container; amodular header core, including: a header core module including at leastone bore hole configured to receive a lead; and an antenna attachmentmodule coupled to the header core; an antenna engaged with the antennaattachment module, the antenna attachment module configured to locatethe antenna with respect to the header core module; and a header shelldisposed around the modular header core and the antenna.
 22. Theimplantable medical device of claim 21, wherein the antenna attachmentmodule includes a first dielectric constant and the header core moduleincludes a second dielectric constant, the first dielectric constantdifferent from the second dielectric constant.
 23. The implantablemedical device of claim 22, wherein the first dielectric constant isless than the second dielectric constant.
 24. The implantable medicaldevice of claim 21, wherein a first mating surface of the antennaattachment module and a second mating surface of the header core moduleengage to form a connection to couple and maintain the position of theantenna attachment module with respect to the header core module whilethe header shell is disposed.
 25. The implantable medical device ofclaim 24, wherein the connection is a tab-and-slot configuration. 26.The implantable medical device of claim 24, wherein the connection is apin-and-hole configuration.
 27. The implantable medical device of claim24, wherein the connection includes a snap-together configuration. 28.The implantable medical device of claim 24, wherein the connectionincludes a mating slide-together configuration.
 29. The implantablemedical device of claim 21, wherein the antenna attachment moduleincludes an antenna attachment feature to couple the antenna to theantenna attachment module.
 30. The implantable medical device of claim29, wherein the antenna attachment feature includes ridges spaced toaccommodate the antenna between the ridges.
 31. The implantable medicaldevice of claim 30, wherein one or more of the ridges of the antennaattachment feature are disposed between portions of the antenna and areconfigured to maintain spacing between the portions of the antenna. 32.The implantable medical device of claim 29, wherein the antennaattachment feature includes a retention feature configured to grip atleast a portion of the antenna.
 33. The implantable medical device ofclaim 29, wherein the antenna attachment feature is configured tomaintain a substantially constant distance between the antenna and apatient.
 34. The implantable medical device of claim 29, wherein theantenna attachment feature includes a channel.
 35. The implantablemedical device of claim 34, wherein the channel includes one or moreportions configured to be crimped to retain the antenna within thechannel.
 36. A method of forming an implantable medical device, themethod comprising: engaging a header core module with an antennaattachment module to form a modular header core; coupling an antenna tothe antenna attachment module; and forming a header shell around themodular header core.
 37. The method of claim 36, wherein engaging theheader core module with the antenna attachment module includesdetachably engaging the header core module with the antenna attachmentmodule.
 38. The method of claim 36, wherein the antenna attachmentmodule is formed from a first material having a first dielectricconstant and the header core module is formed form a second materialhaving a second dielectric constant, wherein the first dielectricconstant is less than the second dielectric constant.
 39. An implantablemedical device comprising: a device container including an electronicmodule within the device container; a header core including an antennaattachment feature; an antenna engaged with the antenna attachmentfeature and electrically coupled with the electronic module within thedevice container, the antenna attachment feature configured to locatethe antenna with respect to the header core; and a molded header shelldisposed around the header core and attached to the device container,the header shell disposed around and configured to retain the antenna.40. The implantable medical device of claim 39, wherein the antennaattachment feature includes a removable portion configured to detachablyengage with the header core.